Why note this info down(Many internet HOW-To's on this subject are not applicable to Redhat 7.3 in using the route command)The aim here is to have two cheap (but powerful) PC based servers. The first PC is the primary server and the second is the backup server (on the same IP network) that becomes live via running scripts if the primary server starts giving problems. The secondary mirrors the primary at regular intervals throughout the day using rsync.If the primary server plays up or suffers a hardware fault:
Using a script on each server, this should take less than 30 seconds to swap over from primary to secondary server. The advantage of using Virtual IP addresses is that the network card can still be running on both servers on their base addresses without conflicting with each other. While it is possible to automate this via "high availability linux" software, this is initially being done manually under the concept of KISS (Keep It Simple Stupid) and to allow the servers to be located in different parts of the building under different power supplies.
If you cannot connect to IP addresses after you transfer them(Summary: some systems and routers seem to be stubbornly holding onto the old IP-MAC address combination in the arp caches. This issue has not been 100% resolved yet and could be due to nuances with the Birkbeck College routers (as some internal computers see the changes immediately - but not external - and/or it could be related to recent kernel upgrades that affect the ethernet drivers). Swapping from mill2/hume2 to mill/hume seems to go OK - but not going visa-versa if mill/hume and been "ccp14live" for quite a while.)Note that if some IP addresses are slow to allow connections on the ccp14live machine. Go into arp on the ccp14dead machine and check if it might be stubbornly holding onto some of the IP addresses in the arp cache. arp -e Use the various arp commands to delete any offfending IP addresses. When this is done (a reboot of the ccp14dead machine may be required?), then the ccp14live machine should then be able to take connections on the offending IP address. e.g,: arp -e
[ccp14@mill bin]# arp -e Address HWtype HWaddress Flags Mask Iface carna.cryst.bbk.ac.uk ether 00:90:27:77:76:BC C eth0 dldata.cryst.bbk.ac.uk ether 00:01:03:41:16:49 C eth0 ftp.ccp14.cryst.bbk.ac. ether 00:01:03:41:16:45 C eth1 redhat.ccp14.cryst.bbk. ether 00:01:03:41:16:45 C eth1 debian.ccp14.cryst.bbk. ether 00:01:03:41:16:45 C eth1 freebsd.ccp14.cryst.bbk ether 00:01:03:41:16:45 C eth1 cerebus.ccp14.cryst.bbk ether 00:01:03:41:16:45 C eth1 ccp14dev.ccp14.cryst.bb ether 00:01:03:41:16:45 C eth1 popper.cryst.bbk.ac.uk ether 00:02:B3:60:09:53 C eth0 ns-l1.cryst.bbk.ac.uk ether 08:00:2B:86:29:38 C eth0 Then something like:
arp --delete dldata.cryst.bbk.ac.uk ping -vc1 -w 2 dldata.cryst.bbk.ac.uk arp --delete debian.ccp14.ac.uk ping -vc1 -w 2 debian.ccp14.ac.uk arp --delete debian.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 debian.ccp14.cryst.bbk.ac.uk arp --delete ftp.ccp14.ac.uk ping -vc1 -w 2 ftp.ccp14.ac.uk arp --delete ftp.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 ftp.ccp14.cryst.bbk.ac.uk arp --delete redhat.ccp14.ac.uk ping -vc1 -w 2 redhat.ccp14.ac.uk arp --delete redhat.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 redhat.ccp14.cryst.bbk.ac.uk arp --delete freebsd.ccp14.ac.uk ping -vc1 -w 2 freebsd.ccp14.ac.uk arp --delete freebsd.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 freebsd.ccp14.cryst.bbk.ac.uk arp --delete cerebus.ccp14.ac.uk ping -vc1 -w 2 cerebus.ccp14.ac.uk arp --delete cerebus.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 cerebus.ccp14.cryst.bbk.ac.uk arp --delete ccp14dev.ccp14.ac.uk ping -vc1 -w 2 ccp14dev.ccp14.ac.uk arp --delete ccp14dev.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 ccp14dev.ccp14.cryst.bbk.ac.uk or: arp --delete dldata.cryst.bbk.ac.uk arp --delete debian.ccp14.ac.uk arp --delete debian.ccp14.cryst.bbk.ac.uk arp --delete ftp.ccp14.ac.uk arp --delete ftp.ccp14.cryst.bbk.ac.uk arp --delete redhat.ccp14.ac.uk arp --delete redhat.ccp14.cryst.bbk.ac.uk arp --delete freebsd.ccp14.ac.uk arp --delete freebsd.ccp14.cryst.bbk.ac.uk arp --delete cerebus.ccp14.ac.uk arp --delete cerebus.ccp14.cryst.bbk.ac.uk arp --delete ccp14dev.ccp14.ac.uk arp --delete ccp14dev.ccp14.cryst.bbk.ac.uk
While not recommended, it is possible to manually (and permanently) add the address and MAC into the arp cache: e.g., on mill2/hume2:
arp -H ether -i eth1 --set ftp.ccp14.cryst.bbk.ac.uk 00:01:03:41:16:45 arp -H ether -i eth1 --set ccp14dev.ccp14.cryst.bbk.ac.uk 00:01:03:41:16:45 arp -H ether -i eth1 --set cerebus.ccp14.cryst.bbk.ac.uk 00:01:03:41:16:45 |
/etc/rc.d/rc.ccp14live (copied to /etc/rc.d/rc.local) startup script that sets Virtual IP addresses and runs the deamons at boot time
#!/bin/sh # # This script will be executed *after* all the other init scripts. # You can put your own initialization stuff in here if you don't # want to do the full Sys V style init stuff. touch /var/lock/subsys/local #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start sshd secureshell deamon echo "Starting sshd secureshell deamon - startup in /etc/rc.d/rc.local" /usr/local/sbin/sshd #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Not working on Redhat 7.3 (did on 7.2) # Make the Atapi CD-ROM and DVDRAM look like a SCSI Device # so you can then write to the DVDRAM using cdrecord: # SuSE Linux 7.0: Writing CDs with ATAPI writers # http://sdb.suse.de/en/sdb/html/mkrapp-cdwriting-7.0.html # Latest CDrecord with DVD support # http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/cdrecord.html #/sbin/modprobe ide-scsi #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ ping -vc1 -w 2 193.61.35.93 if [ $? -eq 1 ]; then echo "ping 193.61.35.93 dldata.cryst.bbk.ac.uk is not alive and pingable - continue with ccp14live script" else echo "warning 193.61.35.93 dldata.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.164 if [ $? -eq 1 ]; then echo "ping 193.61.32.164 debian.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.164 debian.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.162 if [ $? -eq 1 ]; then echo "ping 193.61.32.162 ftp.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.162 ftp.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.163 if [ $? -eq 1 ]; then echo "ping 193.61.32.163 redhat.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.163 redhat.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.165 if [ $? -eq 1 ]; then echo "ping 193.61.32.165 freebsd.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.165 freebsd.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.166 if [ $? -eq 1 ]; then echo "ping 193.61.32.166 cerebus.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.166 cerebus.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.167 if [ $? -eq 1 ]; then echo "ping 193.61.32.167 ccp14dev.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.167 ccp14dev.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi #setting up IP alias interfaces echo "Setting up IP Aliases - script in /etc/rc.d/rc.local" echo "Internal network aliases" #mill.cryst.bbk.ac.uk is eth0 (Internal network) #dldata.cryst.bbk.ac.uk echo "Setting dldata.cryst.bbk.ac.uk 193.61.35.93 IP Aliases internal network" /sbin/ifconfig eth0:1 193.61.35.93 netmask 255.255.254.0 # /sbin/route add -host 193.61.35.93 dev eth0:1 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.35.93 193.61.34.245 ping -vc1 -w 3 -I 193.61.35.93 193.61.32.245 ping -vc1 -w 3 -I 193.61.35.93 193.61.34.17 ping -vc1 -w 3 -I 193.61.35.93 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.35.93 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.35.93 193.61.32.255 sleep 1 #debian.ccp14.cryst.bbk.ac.uk #This is the important one that all the web virtual addresses use echo "Setting debian.ccp14.cryst.bbk.ac.uk 193.61.32.164 IP Aliases" echo "This is the important one that all the web virtual addresses use" /sbin/ifconfig eth1:1 193.61.32.164 # /sbin/route add -host 193.61.32.164 dev eth1:1 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.164 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.164 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.164 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.164 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.164 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.164 193.61.32.255 sleep 1 #hume.cryst.bbk.ac.uk is eth1 (external network) #ftp.ccp14.cryst.bbk.ac.uk echo "Setting ftp.ccp14.cryst.bbk.ac.uk 193.61.32.162 IP Aliases" /sbin/ifconfig eth1:2 193.61.32.162 # /sbin/route add -host 193.61.32.162 dev eth1:2 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.162 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.162 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.162 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.162 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.162 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.162 193.61.32.255 sleep 1 #redhat.ccp14.cryst.bbk.ac.uk echo "Setting redhat.ccp14.cryst.bbk.ac.uk 193.61.32.163 IP Aliases" /sbin/ifconfig eth1:3 193.61.32.163 # /sbin/route add -host 193.61.32.163 dev eth1:3 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.163 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.163 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.163 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.163 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.163 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.163 193.61.32.255 sleep 1 #freebsd.ccp14.cryst.bbk.ac.uk echo "Setting freebsd.ccp14.cryst.bbk.ac.uk 193.61.32.165 IP Aliases" /sbin/ifconfig eth1:4 193.61.32.165 # /sbin/route add -host 193.61.32.165 dev eth1:4 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.165 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.165 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.165 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.165 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.165 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.165 193.61.32.255 sleep 1 #cerebus.ccp14.cryst.bbk.ac.uk echo "Setting cerebus.ccp14.cryst.bbk.ac.uk 193.61.32.166 IP Aliases" /sbin/ifconfig eth1:5 193.61.32.166 # /sbin/route add -host 193.61.32.166 dev eth1:5 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.166 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.166 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.166 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.166 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.166 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.166 193.61.32.255 sleep 1 #ccp14dev.ccp14.cryst.bbk.ac.uk echo "Setting ccp14dev.ccp14.cryst.bbk.ac.uk 193.61.32.167 IP Aliases" /sbin/ifconfig eth1:6 193.61.32.167 # /sbin/route add -host 193.61.32.167 dev eth1:6 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.167 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.167 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.167 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.167 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.167 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.167 193.61.32.255 sleep 1 #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start samba smbd nmbd echo "Starting samba smbd nmbd deamon - startup in /etc/rc.d/rc.local" echo "config file for samba in /usr/local/samba/lib/" /usr/local/samba/bin/smbd -D /usr/local/samba/bin/nmbd -D #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start Apache 2 webserver echo "Starting apache webserver - startup in /etc/rc.d/rc.local" /usr/local/apache2/bin/apachectl start #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start Proftpd ftp server ftp deamon echo "Starting apache webserver - startup in /etc/rc.d/rc.local" /usr/local/sbin/proftpd #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start rsync server deamon echo "Starting rsync server deamon - startup in /etc/rc.d/rc.local" /usr/local/bin/rsync --daemon |
/usr/local/bin/ccp14dead - Script for killing the internet deamons and IP addresses in Runtime#!/bin/sh if [ "`whoami`" != "root" ]; then echo "This script can only run for the root user" exit 127 else echo "You are running as root, thus this script can continue" fi if [ "`ifconfig | grep eth0:1`" = "" ]; then echo "can't kill eth0:1 as it is not up - thus exit or problems will happen" exit 127 else echo "eth0:1 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:1`" = "" ]; then echo "can't kill eth1:1 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:1 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:2`" = "" ]; then echo "can't kill eth1:2 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:2 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:3`" = "" ]; then echo "can't kill eth1:3 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:3 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:4`" = "" ]; then echo "can't kill eth1:4 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:4 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:5`" = "" ]; then echo "can't kill eth1:5 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:5 is already up - continuing to run the ccp14dead script" fi if [ "`ifconfig | grep eth1:6`" = "" ]; then echo "can't kill eth1:6 as it is not up - thus exit or problems will happen" exit 127 else echo "eth1:6 is already up - continuing to run the ccp14dead script" fi # Keep sshd secure shell going as it is not connected to any # virtual IP addresses - only base IP addresses for the internet # cards - check internel card # Kill Samba killall -9 smbd killall -9 nmbd # Kill Apache /usr/local/apache2/bin/apachectl stop # Kill proftpd ftp deamon killall -9 proftpd # Kill rsync deamon killall -9 rsync echo "Sleep for 2 seconds" sleep 2 echo "Killing Enternal network aliases and virtual IP addresses" #ccp14dev.ccp14.cryst.bbk.ac.uk # echo "Setting ccp14dev.ccp14.cryst.bbk.ac.uk 193.61.32.167 IP Aliases" # /sbin/ifconfig eth1:6 193.61.32.167 # /sbin/route add -host 193.61.32.167 dev eth1:6 # #delete route and IP for ccp14dev.ccp14.cryst.bbk.ac.uk 193.61.32.167 # /sbin/route del -host 193.61.32.167 dev eth1:6 /sbin/ifconfig eth1:6 del 193.61.32.167 #cerebus.ccp14.cryst.bbk.ac.uk # echo "Setting cerebus.ccp14.cryst.bbk.ac.uk 193.61.32.166 IP Aliases" # /sbin/ifconfig eth1:5 193.61.32.166 # /sbin/route add -host 193.61.32.166 dev eth1:5 # #delete route and IP for cerebus.ccp14.cryst.bbk.ac.uk 193.61.32.166 # /sbin/route del -host 193.61.32.166 dev eth1:5 /sbin/ifconfig eth1:5 del 193.61.32.166 #freebsd.ccp14.cryst.bbk.ac.uk # echo "Setting freebsd.ccp14.cryst.bbk.ac.uk 193.61.32.165 IP Aliases" # /sbin/ifconfig eth1:4 193.61.32.165 # /sbin/route add -host 193.61.32.165 dev eth1:4 # #delete route and IP for freebsd.ccp14.cryst.bbk.ac.uk 193.61.32.165 # /sbin/route del -host 193.61.32.165 dev eth1:4 /sbin/ifconfig eth1:4 del 193.61.32.165 #redhat.ccp14.cryst.bbk.ac.uk # echo "Setting redhat.ccp14.cryst.bbk.ac.uk 193.61.32.163 IP Aliases" # /sbin/ifconfig eth1:3 193.61.32.163 # /sbin/route add -host 193.61.32.163 dev eth1:2 # #delete route and IP for redhat.ccp14.cryst.bbk.ac.uk 193.61.32.163 # /sbin/route del -host 193.61.32.163 dev eth1:3 /sbin/ifconfig eth1:3 del 193.61.32.163 #ftp.ccp14.cryst.bbk.ac.uk # echo "Setting ftp.ccp14.cryst.bbk.ac.uk 193.61.32.162 IP Aliases" # /sbin/ifconfig eth1:2 193.61.32.162 # /sbin/route add -host 193.61.32.162 dev eth1:1 # #delete route and IP for ftp.ccp14.cryst.bbk.ac.uk 193.61.32.162 # /sbin/route del -host 193.61.32.162 dev eth1:2 /sbin/ifconfig eth1:2 del 193.61.32.162 #debian.ccp14.cryst.bbk.ac.uk #This is the important one that all the main web virtual addresses use # echo "Setting debian.ccp14.cryst.bbk.ac.uk 193.61.32.164 IP Aliases" # echo "This is the important one that all the web virtual addresses use" # /sbin/ifconfig eth1:1 193.61.32.164 # /sbin/route add -host 193.61.32.164 dev eth1:1 # #delete route and IP for debian.ccp14.cryst.bbk.ac.uk 193.61.32.164 # /sbin/route del -host 193.61.32.164 dev eth1:1 /sbin/ifconfig eth1:1 del 193.61.32.164 echo "Internal network aliases" #mill.cryst.bbk.ac.uk is eth0 (Internal network) #dldata.cryst.bbk.ac.uk # echo "Setting dldata.cryst.bbk.ac.uk 193.61.35.93 IP Aliases internal network" # /sbin/ifconfig eth0:1 193.61.35.93 # /sbin/route add -host 193.61.35.93 dev eth0:1 # #delete route and IP for dldata.cryst.bbk.ac.uk 193.61.35.93 # /sbin/route del -host 193.61.35.93 dev eth0:1 /sbin/ifconfig eth0:1 del 193.61.35.93 echo "Done - deamons killed (except sshd) and virtual IPs cancelled" #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ # copy ccp14dead crontab and startup files to where they have to be /bin/cp /etc/rc.d/rc.ccp14dead /etc/rc.d/rc.local echo "Done - copied /etc/rc.d rc.ccp14dead to rc.local" /bin/cp ~root/.crontabccp14dead /var/spool/cron/root echo "Copied root crontab file ~root/.crontabccp14dead to /var/spool/cron/root" /bin/cp ~ccp14/.crontabccp14mirrordead /var/spool/cron/ccp14 echo "Copied ccp14 crontab file ~ccp14/.crontabccp14mirrordead to /var/spool/cron/ccp14" # ======================================================= # ======================================================= echo "Do some arp stuff to make sure arp cache is reset - due to previous problems" arp --delete dldata.cryst.bbk.ac.uk arp --delete debian.ccp14.ac.uk arp --delete debian.ccp14.cryst.bbk.ac.uk arp --delete ftp.ccp14.ac.uk arp --delete ftp.ccp14.cryst.bbk.ac.uk arp --delete redhat.ccp14.ac.uk arp --delete redhat.ccp14.cryst.bbk.ac.uk arp --delete freebsd.ccp14.ac.uk arp --delete freebsd.ccp14.cryst.bbk.ac.uk arp --delete cerebus.ccp14.ac.uk arp --delete cerebus.ccp14.cryst.bbk.ac.uk arp --delete ccp14dev.ccp14.ac.uk arp --delete ccp14dev.ccp14.cryst.bbk.ac.uk echo "Have run the arp clear commands" |
/usr/local/bin/ccp14live - script for making CCP14live in Runtime#!/bin/sh # if [ "`whoami`" != "root" ]; then echo "This script can only run for the root user" exit 127 else echo "You are running as root, thus this script can continue" fi if [ "`ifconfig | grep eth0:1`" = "" ]; then echo "eth0:1 is not up" else echo "eth0:1 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:1`" = "" ]; then echo "eth1:1 is not up" else echo "eth1:1 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:2`" = "" ]; then echo "eth1:2 is not up" else echo "eth1:2 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:3`" = "" ]; then echo "eth1:3 is not up" else echo "eth1:3 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:4`" = "" ]; then echo "eth1:4 is not up" else echo "eth1:4 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:5`" = "" ]; then echo "eth1:5 is not up" else echo "eth1:5 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi if [ "`ifconfig | grep eth1:6`" = "" ]; then echo "eth1:6 is not up" else echo "eth1:6 is already up - exiting as ccp14 is already alive on this machine" exit 127 fi sleep 1 #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ ping -vc1 -w 2 193.61.35.93 if [ $? -eq 1 ]; then echo "ping 193.61.35.93 dldata.cryst.bbk.ac.uk is not alive and pingable - continue with ccp14live script" else echo "warning 193.61.35.93 dldata.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.164 if [ $? -eq 1 ]; then echo "ping 193.61.32.164 debian.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.164 debian.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.162 if [ $? -eq 1 ]; then echo "ping 193.61.32.162 ftp.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.162 ftp.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.163 if [ $? -eq 1 ]; then echo "ping 193.61.32.163 redhat.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.163 redhat.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.165 if [ $? -eq 1 ]; then echo "ping 193.61.32.165 freebsd.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.165 freebsd.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.166 if [ $? -eq 1 ]; then echo "ping 193.61.32.166 cerebus.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.166 cerebus.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi ping -vc1 -w 2 193.61.32.167 if [ $? -eq 1 ]; then echo "ping 193.61.32.167 ccp14dev.ccp14.cryst.bbk.ac.uk is not pingable - continue with ccp14live script" else echo "warning 193.61.32.167 ccp14dev.ccp14.cryst.bbk.ac.uk is alive and pingable! - exiting ccp14live script" exit 127 fi #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #setting up IP alias interfaces echo "Setting up IP Aliases - script in /etc/rc.d/rc.local" echo "Internal network aliases" #mill.cryst.bbk.ac.uk is eth0 (Internal network) #dldata.cryst.bbk.ac.uk echo "Setting dldata.cryst.bbk.ac.uk 193.61.35.93 IP Aliases internal network" /sbin/ifconfig eth0:1 193.61.35.93 netmask 255.255.254.0 # /sbin/route add -host 193.61.35.93 dev eth0:1 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.35.93 193.61.34.245 ping -vc1 -w 3 -I 193.61.35.93 193.61.32.245 ping -vc1 -w 3 -I 193.61.35.93 193.61.34.17 ping -vc1 -w 3 -I 193.61.35.93 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.35.93 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.35.93 193.61.32.255 sleep 1 #debian.ccp14.cryst.bbk.ac.uk #This is the important one that all the web virtual addresses use echo "Setting debian.ccp14.cryst.bbk.ac.uk 193.61.32.164 IP Aliases" echo "This is the important one that all the web virtual addresses use" /sbin/ifconfig eth1:1 193.61.32.164 # /sbin/route add -host 193.61.32.164 dev eth1:1 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.164 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.164 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.164 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.164 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.164 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.164 193.61.32.255 sleep 1 #hume.cryst.bbk.ac.uk is eth1 (external network) #ftp.ccp14.cryst.bbk.ac.uk echo "Setting ftp.ccp14.cryst.bbk.ac.uk 193.61.32.162 IP Aliases" /sbin/ifconfig eth1:2 193.61.32.162 # /sbin/route add -host 193.61.32.162 dev eth1:2 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.162 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.162 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.162 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.162 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.162 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.162 193.61.32.255 sleep 1 #redhat.ccp14.cryst.bbk.ac.uk echo "Setting redhat.ccp14.cryst.bbk.ac.uk 193.61.32.163 IP Aliases" /sbin/ifconfig eth1:3 193.61.32.163 # /sbin/route add -host 193.61.32.163 dev eth1:3 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.163 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.163 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.163 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.163 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.163 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.163 193.61.32.255 sleep 1 #freebsd.ccp14.cryst.bbk.ac.uk echo "Setting freebsd.ccp14.cryst.bbk.ac.uk 193.61.32.165 IP Aliases" /sbin/ifconfig eth1:4 193.61.32.165 # /sbin/route add -host 193.61.32.165 dev eth1:4 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.165 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.165 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.165 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.165 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.165 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.165 193.61.32.255 sleep 1 #cerebus.ccp14.cryst.bbk.ac.uk echo "Setting cerebus.ccp14.cryst.bbk.ac.uk 193.61.32.166 IP Aliases" /sbin/ifconfig eth1:5 193.61.32.166 # /sbin/route add -host 193.61.32.166 dev eth1:5 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.166 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.166 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.166 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.166 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.166 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.166 193.61.32.255 sleep 1 #ccp14dev.ccp14.cryst.bbk.ac.uk echo "Setting ccp14dev.ccp14.cryst.bbk.ac.uk 193.61.32.167 IP Aliases" /sbin/ifconfig eth1:6 193.61.32.167 # /sbin/route add -host 193.61.32.167 dev eth1:6 echo "Ping the gateways and DNS once to clear the ARP cache" sleep 1 ping -vc1 -w 3 -I 193.61.32.167 193.61.34.245 ping -vc1 -w 3 -I 193.61.32.167 193.61.32.245 ping -vc1 -w 3 -I 193.61.32.167 193.61.34.17 ping -vc1 -w 3 -I 193.61.32.167 193.61.35.38 echo "Ping the internal and external broadcast address once to clear the ARP cache" sleep 1 ping -vc1 -b -w 3 -I 193.61.32.167 193.61.35.255 ping -vc1 -b -w 3 -I 193.61.32.167 193.61.32.255 sleep 1 #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start samba smbd nmbd echo "Starting samba smbd nmbd deamon - startup in /etc/rc.d/rc.local" echo "config file for samba in /usr/local/samba/lib/" /usr/local/samba/bin/smbd -D /usr/local/samba/bin/nmbd -D #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start Apache 2 webserver echo "Starting apache webserver - startup in /etc/rc.d/rc.local" /usr/local/apache2/bin/apachectl start #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start Proftpd ftp server ftp deamon echo "Starting apache webserver - startup in /etc/rc.d/rc.local" /usr/local/sbin/proftpd #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Start rsync server deamon echo "Starting rsync server deamon - startup in /etc/rc.d/rc.local" /usr/local/bin/rsync --daemon echo "Started rsync server deamon - startup in /etc/rc.d/rc.local" /bin/cp /etc/rc.d/rc.ccp14live /etc/rc.d/rc.local echo "Done - copied /etc/rc.d rc.ccp14dead to rc.local" #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ #Be paranoid about the arp cache echo "Be paranoid about the arp cache" arp --delete dldata.cryst.bbk.ac.uk ping -vc1 -w 2 dldata.cryst.bbk.ac.uk arp --delete debian.ccp14.ac.uk ping -vc1 -w 2 debian.ccp14.ac.uk arp --delete debian.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 debian.ccp14.cryst.bbk.ac.uk arp --delete ftp.ccp14.ac.uk ping -vc1 -w 2 ftp.ccp14.ac.uk arp --delete ftp.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 ftp.ccp14.cryst.bbk.ac.uk arp --delete redhat.ccp14.ac.uk ping -vc1 -w 2 redhat.ccp14.ac.uk arp --delete redhat.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 redhat.ccp14.cryst.bbk.ac.uk arp --delete freebsd.ccp14.ac.uk ping -vc1 -w 2 freebsd.ccp14.ac.uk arp --delete freebsd.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 freebsd.ccp14.cryst.bbk.ac.uk arp --delete cerebus.ccp14.ac.uk ping -vc1 -w 2 cerebus.ccp14.ac.uk arp --delete cerebus.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 cerebus.ccp14.cryst.bbk.ac.uk arp --delete ccp14dev.ccp14.ac.uk ping -vc1 -w 2 ccp14dev.ccp14.ac.uk arp --delete ccp14dev.ccp14.cryst.bbk.ac.uk ping -vc1 -w 2 ccp14dev.ccp14.cryst.bbk.ac.uk echo "Finished being paranoid about the arp cache" |
man ifconfig - for enabled and disabling Virtual IP addresses
[root@mill rc.d]# ifconfig --help Usage: ifconfig [-a] [-i] [-v] [-s] <interface> [[<AF>] <address>] [add <address>[/<prefixlen>]] [del <address>[/<prefixlen>]] [[-]broadcast [<address>]] [[-]pointopoint [<address>]] [netmask <address>] [dstaddr <address>] [tunnel <address>] [outfill <NN>] [keepalive <NN>] [hw <HW> <address>] [metric <NN>] [mtu <NN>] [[-]trailers] [[-]arp] [[-]allmulti] [multicast] [[-]promisc] [mem_start <NN>] [io_addr <NN>] [irq <NN>] [media <type>] [txqueuelen <NN>] [[-]dynamic] [up|down] ...
IFCONFIG(8) Linux Programmer's Manual IFCONFIG(8) NAME ifconfig - configure a network interface SYNOPSIS ifconfig [interface] ifconfig interface [aftype] options | address ... DESCRIPTION Ifconfig is used to configure the kernel-resident network interfaces. It is used at boot time to set up interfaces as necessary. After that, it is usually only needed when debugging or when system tuning is needed. If no arguments are given, ifconfig displays the status of the currently active interfaces. If a single interface argument is given, it displays the status of the given interface only; if a single -a argument is given, it dis- plays the status of all interfaces, even those that are down. Otherwise, it configures an interface. Address Families If the first argument after the interface name is recog- nized as the name of a supported address family, that address family is used for decoding and displaying all protocol addresses. Currently supported address families include inet (TCP/IP, default), inet6 (IPv6), ax25 (AMPR Packet Radio), ddp (Appletalk Phase 2), ipx (Novell IPX) and netrom (AMPR Packet radio). interface The name of the interface. This is usually a driver name followed by a unit number, for example eth0 for the first Ethernet interface. up This flag causes the interface to be activated. It is implicitly specified if an address is assigned to the interface. down This flag causes the driver for this interface to be shut down. [-]arp Enable or disable the use of the ARP protocol on this interface. [-]promisc Enable or disable the promiscuous mode of the interface. If selected, all packets on the network will be received by the interface. [-]allmulti Enable or disable all-multicast mode. If selected, all multicast packets on the network will be received by the interface. metric N This parameter sets the interface metric. mtu N This parameter sets the Maximum Transfer Unit (MTU) of an interface. dstaddr addr Set the remote IP address for a point-to-point link (such as PPP). This keyword is now obsolete; use the pointopoint keyword instead. netmask addr Set the IP network mask for this interface. This value defaults to the usual class A, B or C network mask (as derived from the interface IP address), but it can be set to any value. add addr/prefixlen Add an IPv6 address to an interface. del addr/prefixlen Remove an IPv6 address from an interface. tunnel aa.bb.cc.dd Create a new SIT (IPv6-in-IPv4) device, tunnelling to the given destination. irq addr Set the interrupt line used by this device. Not all devices can dynamically change their IRQ set- ting. io_addr addr Set the start address in I/O space for this device. mem_start addr Set the start address for shared memory used by this device. Only a few devices need this. media type Set the physical port or medium type to be used by the device. Not all devices can change this set- ting, and those that can vary in what values they support. Typical values for type are 10base2 (thin Ethernet), 10baseT (twisted-pair 10Mbps Ethernet), AUI (external transceiver) and so on. The special medium type of auto can be used to tell the driver to auto-sense the media. Again, not all drivers can do this. [-]broadcast [addr] If the address argument is given, set the protocol broadcast address for this interface. Otherwise, set (or clear) the IFF_BROADCAST flag for the interface. [-]pointopoint [addr] This keyword enables the point-to-point mode of an interface, meaning that it is a direct link between two machines with nobody else listening on it. If the address argument is also given, set the pro- tocol address of the other side of the link, just like the obsolete dstaddr keyword does. Otherwise, set or clear the IFF_POINTOPOINT flag for the interface. hw class address Set the hardware address of this interface, if the device driver supports this operation. The keyword must be followed by the name of the hardware class and the printable ASCII equivalent of the hardware address. Hardware classes currently supported include ether (Ethernet), ax25 (AMPR AX.25), ARCnet and netrom (AMPR NET/ROM). multicast Set the multicast flag on the interface. This should not normally be needed as the drivers set the flag correctly themselves. address The IP address to be assigned to this interface. txqueuelen length Set the length of the transmit queue of the device. It is useful to set this to small values for slower devices with a high latency (modem links, ISDN) to prevent fast bulk transfers from disturbing inter- active traffic like telnet too much. NOTES Since kernel release 2.2 there are no explicit interface statistics for alias interfaces anymore. The statistics printed for the original address are shared with all alias addresses on the same device. If you want per-address statistics you should add explicit accounting rules for the address using the ipchains(8) command. NOTES Since kernel release 2.2 there are no explicit interface statistics for alias interfaces anymore. The statistics printed for the original address are shared with all alias addresses on the same device. If you want per-address statistics you should add explicit accounting rules for the address using the ipchains(8) command. Interrupt problems with Ethernet device drivers fail with EAGAIN. See http://cesdis.gsfc.nasa.gov/linux/misc/irq- conflict.html for more information. FILES /proc/net/socket /proc/net/dev /proc/net/if_inet6 BUGS While appletalk DDP and IPX addresses will be displayed they cannot be altered by this command. SEE ALSO route(8), netstat(8), arp(8), rarp(8), ipchains(8) AUTHORS Fred N. van Kempen, [waltje@uwalt.nl.mugnet.org] Alan Cox, [Alan.Cox@linux.org] Phil Blundell, [Philip.Blundell@pobox.com] Andi Kleen net-tools 14 August 2000 IFCONFIG(8)
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man route - for enabled and disabling Virtual IP addresses
[root@mill rc.d]# route --help Usage: route [-nNvee] [-FC] [<AF>] List kernel routing tables route [-v] [-FC] {add|del|flush} ... Modify routing table for AF. route {-h|--help} [<AF>] Detailed usage syntax for specified AF. route {-V|--version} Display version/author and exit. -v, --verbose be verbose -n, --numeric don't resolve names -e, --extend display other/more information -F, --fib display Forwarding Information Base (default) -C, --cache display routing cache instead of FIB <AF>=Use '-A <af>' or '--<af>'; default: inet List of possible address families (which support routing): inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25) netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP) x25 (CCITT X.25)
ROUTE(8) Linux Programmer's Manual ROUTE(8) NAME route - show / manipulate the IP routing table SYNOPSIS route [-CFvnee] route [-v] [-A family] add [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W] [irtt I] [reject] [mod] [dyn] [reinstate] [[dev] If] route [-v] [-A family] del [-net|-host] target [gw Gw] [netmask Nm] [metric N] [[dev] If] route [-V] [--version] [-h] [--help] DESCRIPTION Route manipulates the kernel's IP routing tables. Its primary use is to set up static routes to specific hosts or networks via an interface after it has been configured with the ifconfig(8) program. When the add or del options are used, route modifies the routing tables. Without these options, route displays the current contents of the routing tables. OPTIONS -A family use the specified address family (eg `inet'; use `route --help' for a full list). -F operate on the kernel's FIB (Forwarding Information Base) routing table. This is the default. -C operate on the kernel's routing cache. -v select verbose operation. -n show numerical addresses instead of trying to determine symbolic host names. This is useful if you are trying to determine why the route to your nameserver has vanished. -e use netstat(8)-format for displaying the routing table. -ee will generate a very long line with all parameters from the routing table. del delete a route. add add a new route. target the destination network or host. You can provide IP addresses in dotted decimal or host/network names. -net the target is a network. -host the target is a host. netmask NM when adding a network route, the netmask to be used. gw GW route packets via a gateway. NOTE: The specified gateway must be reachable first. This usually means that you have to set up a static route to the gate- way beforehand. If you specify the address of one of your local interfaces, it will be used to decide about the interface to which the packets should be routed to. This is a BSDism compatibility hack. metric M set the metric field in the routing table (used by routing daemons) to M. mss M set the TCP Maximum Segment Size (MSS) for connec- tions over this route to M bytes. The default is the device MTU minus headers, or a lower MTU when path mtu discovery occured. This setting can be used to force smaller TCP packets on the other end when path mtu discovery does not work (usually because of misconfigured firewalls that block ICMP Fragmentation Needed) window W set the TCP window size for connections over this route to W bytes. This is typically only used on AX.25 networks and with drivers unable to handle back to back frames. irtt I set the initial round trip time (irtt) for TCP con- nections over this route to I milliseconds (1-12000). This is typically only used on AX.25 networks. If omitted the RFC 1122 default of 300ms is used. reject install a blocking route, which will force a route lookup to fail. This is for example used to mask out networks before using the default route. This is NOT for firewalling. mod, dyn, reinstate install a dynamic or modified route. These flags are for diagnostic purposes, and are generally only set by routing daemons. dev If force the route to be associated with the specified device, as the kernel will otherwise try to deter- mine the device on its own (by checking already existing routes and device specifications, and where the route is added to). In most normal net- works you won't need this. If dev If is the last option on the command line, the word dev may be omitted, as it's the default. Otherwise the order of the route modifiers (metric - netmask - gw - dev) doesn't matter. EXAMPLES route add -net 127.0.0.0 adds the normal loopback entry, using netmask 255.0.0.0 (class A net, determined from the desti- nation address) and associated with the "lo" device (assuming this device was prviously set up cor- rectly with ifconfig(8)). route add -net 192.56.76.0 netmask 255.255.255.0 dev eth0 adds a route to the network 192.56.76.x via "eth0". The Class C netmask modifier is not really neces- sary here because 192.* is a Class C IP address. The word "dev" can be omitted here. route add default gw mango-gw adds a default route (which will be used if no other route matches). All packets using this route will be gatewayed through "mango-gw". The device which will actually be used for that route depends on how we can reach "mango-gw" - the static route to "mango-gw" will have to be set up before. route add ipx4 sl0 Adds the route to the "ipx4" host via the SLIP interface (assuming that "ipx4" is the SLIP host). route add -net 192.57.66.0 netmask 255.255.255.0 gw ipx4 This command adds the net "192.57.66.x" to be gate- wayed through the former route to the SLIP inter- face. route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0 This is an obscure one documented so people know how to do it. This sets all of the class D (multi- cast) IP routes to go via "eth0". This is the cor- rect normal configuration line with a multicasting kernel. route add -net 10.0.0.0 netmask 255.0.0.0 reject This installs a rejecting route for the private network "10.x.x.x." OUTPUT The output of the kernel routing table is organized in the following columns Destination The destination network or destination host. Gateway The gateway address or '*' if none set. Genmask The netmask for the destination net; '255.255.255.255' for a host destination and '0.0.0.0' for the default route. Flags Possible flags include U (route is up) H (target is a host) G (use gateway) R (reinstate route for dynamic routing) D (dynamically installed by daemon or redirect) M (modified from routing daemon or redirect) A (installed by addrconf) C (cache entry) ! (reject route) Metric The 'distance' to the target (usually counted in hops). It is not used by recent kernels, but may be needed by routing daemons. Ref Number of references to this route. (Not used in the Linux kernel.) Use Count of lookups for the route. Depending on the use of -F and -C this will be either route cache misses (-F) or hits (-C). Iface Interface to which packets for this route will be sent. MSS Default maximum segement size for TCP connections over this route. Window Default window size for TCP connections over this route. irtt Initial RTT (Round Trip Time). The kernel uses this to guess about the best TCP protocol parameters without waiting on (possibly slow) answers. HH (cached only) The number of ARP entries and cached routes that refer to the hardware header cache for the cached route. This will be -1 if a hardware address is not needed for the interface of the cached route (e.g. lo). HH (cached only) The number of ARP entries and cached routes that refer to the hardware header cache for the cached route. This will be -1 if a hardware address is not needed for the interface of the cached route (e.g. lo). Arp (cached only) Whether or not the hardware address for the cached route is up to date. FILES /proc/net/ipv6_route /proc/net/route /proc/net/rt_cache SEE ALSO ifconfig(8), netstat(8), arp(8), rarp(8) HISTORY Route for Linux was originally written by Fred N. van Kempen, [waltje@uwalt.nl.mugnet.org] and then modified by Johannes Stille and Linus Torvalds for pl15. Alan Cox added the mss and window options for Linux 1.1.22. irtt support and merged with netstat from Bernd Eckenfels. AUTHOR Currently maintained by Phil Blundell [Philip.Blun- dell@pobox.com]. net-tools 2 January 2000 ROUTE(8)
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