Short story: I've got a faulty cisco 1811 on my hands. It's a dual wan fixed configuration router. I had it setup with route maps to do load balancing. It works but every couple of hours it shits itself and needs rebooting. I need to take it out of it's current position on the network.
So what I've done (for temporary purposes) is built up a new box, installed debian, iproute2 and configured iptables.
I've got two internet connections, both on separate phone lines, both to separate linksys routers. The routers are in bridged mode. The new box has 3 NICS (2 nics for connecting to each router in bridge mode) and one for internal network. I've used pppoeconf to setup two new pppoe connections. That all works.
It seems to work when only one connection is up, but not when both are up. I have a feeling that it doesn't know which interface to process the packet on. I've read many documents about split access and load balancing but I can't get it working.
gateway:~# ifconfig -a eth1 Link encap:Ethernet HWaddr 00:24:8c:4e:31:e7 inet addr:192.168.5.254 Bcast:192.168.5.255 Mask:255.255.255.0 inet6 addr: fe80::224:8cff:fe4e:31e7/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:3494 errors:0 dropped:0 overruns:0 frame:0 TX packets:3553 errors:0 dropped:0 overruns:0 carrier:1 collisions:0 txqueuelen:1000 RX bytes:633209 (618.3 KiB) TX bytes:1668656 (1.5 MiB) Interrupt:219 eth2 Link encap:Ethernet HWaddr 00:40:f4:ba:c4:41 inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::240:f4ff:feba:c441/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:365 errors:0 dropped:0 overruns:0 frame:0 TX packets:377 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:57190 (55.8 KiB) TX bytes:85824 (83.8 KiB) Interrupt:16 Base address:0xe800 eth3 Link encap:Ethernet HWaddr 00:60:67:72:40:42 inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::260:67ff:fe72:4042/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2287 errors:0 dropped:0 overruns:0 frame:0 TX packets:1971 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1414715 (1.3 MiB) TX bytes:425185 (415.2 KiB) Interrupt:17 Base address:0xe400 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:150 errors:0 dropped:0 overruns:0 frame:0 TX packets:150 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:15596 (15.2 KiB) TX bytes:15596 (15.2 KiB) ppp0 Link encap:Point-to-Point Protocol inet addr:150.101.177.X P-t-P:150.101.180.24 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1 RX packets:1955 errors:0 dropped:0 overruns:0 frame:0 TX packets:1446 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:1344970 (1.2 MiB) TX bytes:353725 (345.4 KiB) ppp1 Link encap:Point-to-Point Protocol inet addr:150.101.179.X P-t-P:150.101.180.143 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1 RX packets:28 errors:0 dropped:0 overruns:0 frame:0 TX packets:37 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:6691 (6.5 KiB) TX bytes:10285 (10.0 KiB) I can dial both connections and they both answer and authenticate successfully.
gateway:~# cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface allow-hotplug eth1 iface eth1 inet static address 192.168.5.254 netmask 255.255.255.0 broadcast 192.168.5.255 auto eth3 allow-hotplug eth3 iface eth3 inet dhcp auto eth2 allow-hotplug eth2 iface eth2 inet dhcp auto dsl-provider1 iface dsl-provider1 inet ppp pre-up /sbin/ifconfig eth3 up # line maintained by pppoeconf #post-up ip route add 150.101.180.143 dev eth1 src 150.101.179.X table T2 #post-up ip route add default via 150.101.180.143 table T2 #post-up ip rule add from 150.101.179.X table T2 #post-down ip rule del from 150.101.179.X table T2 provider dsl-provider1 auto dsl-provider iface dsl-provider inet ppp pre-up /sbin/ifconfig eth2 up # line maintained by pppoeconf #post-up ip route add 150.101.180.24 dev eth2 src 150.101.177.X table T1 #post-up ip route add default via 150.101.180.24 table T1 #post-up ip rule add from 150.101.177.X table T1 #post-down ip rule del from 150.101.177.X table T1 provider dsl-provider gateway:~# As you can see above I've commented out the post-up's and down's to set the ip routes Should I be using ethX as the dev in ip route commands? or should it be pppX? I also note that when any interface changes, the ip routes are refreshed and changes lost. And here is my rt_tables file.
gateway:~# cat /etc/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 200 uplink1 201 uplink2 100 T1 101 T2 gateway:~# This is my ip tables script. I know it needs changing, (especially the default rules) but that aside: - It works after one connection is up, and
#!/bin/sh INTIF="eth1" EXTIF="ppp0" EXTIF2="ppp1" EXTIP="`/sbin/ifconfig ppp0 | grep 'inet addr' | awk '{print $2}' | sed -e 's/.*://'`" EXTIP2="`/sbin/ifconfig ppp1 | grep 'inet addr' | awk '{print $2}' | sed -e 's/.*://'`" /sbin/depmod -a /sbin/modprobe ip_tables /sbin/modprobe ip_conntrack /sbin/modprobe ip_conntrack_ftp /sbin/modprobe ip_conntrack_irc /sbin/modprobe iptable_nat /sbin/modprobe ip_nat_ftp echo "1" > /proc/sys/net/ipv4/ip_forward echo "1" > /proc/sys/net/ipv4/ip_dynaddr iptables -P INPUT ACCEPT iptables -F INPUT iptables -P OUTPUT ACCEPT iptables -F OUTPUT iptables -P FORWARD DROP iptables -F FORWARD iptables -t nat -F iptables -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT iptables -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE iptables -A FORWARD -i $EXTIF2 -o $INTIF -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -i $INTIF -o $EXTIF2 -j ACCEPT iptables -t nat -A POSTROUTING -o $EXTIF2 -j MASQUERADE #Transparent Proxy iptables -t nat -A PREROUTING -i $INTIF -p tcp --dport 80 -j REDIRECT --to-port 3128 #Mail iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 25 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 25 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 25 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 25 -j DNAT --to 192.168.5.4 #HTTPS (webmail) iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 443 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 443 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 443 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 443 -j DNAT --to 192.168.5.4 #IMAPS iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 993 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 993 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 993 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 993 -j DNAT --to 192.168.5.4 #POP3 iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 110 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 110 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 110 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 110 -j DNAT --to 192.168.5.4 #VPN iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 1723 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 1723 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 1723 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 1723 -j DNAT --to 192.168.5.4 #HTTP iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 80 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 80 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 80 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 80 -j DNAT --to 192.168.5.4 #Bridgit iptables -A FORWARD -i $EXTIF -o $INTIF -d 192.168.5.4 -p tcp --dport 8080 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF -d $EXTIP -p tcp --dport 8080 -j DNAT --to 192.168.5.4 iptables -A FORWARD -i $EXTIF2 -o $INTIF -d 192.168.5.4 -p tcp --dport 8080 -j ACCEPT iptables -t nat -A PREROUTING -i $EXTIF2 -d $EXTIP2 -p tcp --dport 8080 -j DNAT --to 192.168.5.4 #GATEWAY2="150.101.180.143" #GATEWAY="150.101.180.24" #ip route add $GATEWAY dev $EXTIF src $EXTIP table T1 #ip route add default via $GATEWAY table T1 #ip route add $GATEWAY2 dev $EXTIF2 src $EXTIP2 table T2 #ip route add default via $GATEWAY2 table T2 #ip rule add from $EXTIP table T1 #ip rule add from $EXTIP2 table T2 #ip route add default scope global nexthop via $GATEWAY dev $EXTIF weight 1 nexthop via $GATEWAY2 dev $EXTIF2 weight 1 Any ideas would be fantastic.
Thanks,
Mike
EDIT: Here is the requested commands and output which were requested from the comments on this question. Thanks!
Explanation: I've turned on the machine with both interfaces automatically coming up on bootup (ppp dials and connects automatically). You can see as soon as I turn off one interface it works.
login as: root [email protected]'s password: Linux gateway 2.6.26-2-686 #1 SMP Thu Sep 16 19:35:51 UTC 2010 i686 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Last login: Wed Nov 3 04:07:28 2010 from 192.168.5.38 gateway:~# ping google.com ping: unknown host google.com gateway:~# ip route 150.101.180.24 dev ppp0 proto kernel scope link src 150.101.179.XXX 150.101.180.24 dev ppp1 proto kernel scope link src 150.101.177.XXX 192.168.5.0/24 dev eth1 proto kernel scope link src 192.168.5.254 192.168.1.0/24 dev eth2 proto kernel scope link src 192.168.1.2 192.168.1.0/24 dev eth3 proto kernel scope link src 192.168.1.3 default via 192.168.1.254 dev eth3 default via 192.168.1.254 dev eth2 default dev ppp1 scope link default dev ppp0 scope link gateway:~# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 10 00 link/ether 00:24:8c:4e:31:e7 brd ff:ff:ff:ff:ff:ff 3: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN ql en 1000 link/ether 00:40:f4:ba:c4:41 brd ff:ff:ff:ff:ff:ff 4: eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN ql en 1000 link/ether 00:60:67:72:40:42 brd ff:ff:ff:ff:ff:ff 5: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UN KNOWN qlen 3 link/ppp 6: ppp1: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UN KNOWN qlen 3 link/ppp gateway:~# clear gateway:~# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:24:8c:4e:31:e7 brd ff:ff:ff:ff:ff:ff 3: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:40:f4:ba:c4:41 brd ff:ff:ff:ff:ff:ff 4: eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:60:67:72:40:42 brd ff:ff:ff:ff:ff:ff 5: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN qlen 3 link/ppp 6: ppp1: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN qlen 3 link/ppp gateway:~# ip neigh show 192.168.5.38 dev eth1 lladdr 00:1d:60:0a:cb:23 DELAY 192.168.1.254 dev eth3 lladdr 00:04:ed:a9:07:81 REACHABLE 192.168.1.254 dev eth2 lladdr 00:04:ed:aa:cd:45 REACHABLE 192.168.5.43 dev eth1 lladdr 00:08:5d:03:b3:3f STALE 192.168.5.4 dev eth1 lladdr 00:1e:0b:1c:4e:60 STALE gateway:~# ip route get 5.5.5.5 5.5.5.5 via 192.168.1.254 dev eth3 src 192.168.1.3 cache mtu 1500 advmss 1460 hoplimit 64 gateway:~# ping google.com ping: unknown host google.com gateway:~# ping 4.2.2.2 PING 4.2.2.2 (4.2.2.2) 56(84) bytes of data. From 192.168.1.254 icmp_seq=1 Destination Net Unreachable From 192.168.1.254 icmp_seq=2 Destination Net Unreachable ^C --- 4.2.2.2 ping statistics --- 2 packets transmitted, 0 received, +2 errors, 100% packet loss, time 1003ms gateway:~# ifconfig -a eth1 Link encap:Ethernet HWaddr 00:24:8c:4e:31:e7 inet addr:192.168.5.254 Bcast:192.168.5.255 Mask:255.255.255.0 inet6 addr: fe80::224:8cff:fe4e:31e7/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:739 errors:0 dropped:0 overruns:0 frame:0 TX packets:303 errors:0 dropped:0 overruns:0 carrier:2 collisions:0 txqueuelen:1000 RX bytes:59730 (58.3 KiB) TX bytes:35821 (34.9 KiB) Interrupt:219 eth2 Link encap:Ethernet HWaddr 00:40:f4:ba:c4:41 inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::240:f4ff:feba:c441/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:152 errors:0 dropped:0 overruns:0 frame:0 TX packets:119 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:15328 (14.9 KiB) TX bytes:8207 (8.0 KiB) Interrupt:16 Base address:0xe800 eth3 Link encap:Ethernet HWaddr 00:60:67:72:40:42 inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::260:67ff:fe72:4042/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:521 errors:0 dropped:0 overruns:0 frame:0 TX packets:758 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:48899 (47.7 KiB) TX bytes:57096 (55.7 KiB) Interrupt:17 Base address:0xe400 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:20 errors:0 dropped:0 overruns:0 frame:0 TX packets:20 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1160 (1.1 KiB) TX bytes:1160 (1.1 KiB) ppp0 Link encap:Point-to-Point Protocol inet addr:150.101.179.XXX P-t-P:150.101.180.24 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1 RX packets:61 errors:0 dropped:0 overruns:0 frame:0 TX packets:3 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:7454 (7.2 KiB) TX bytes:54 (54.0 B) ppp1 Link encap:Point-to-Point Protocol inet addr:150.101.177.XXX P-t-P:150.101.180.24 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1 RX packets:127 errors:0 dropped:0 overruns:0 frame:0 TX packets:3 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:6278 (6.1 KiB) TX bytes:54 (54.0 B) gateway:~# ifdown eth2 There is already a pid file /var/run/dhclient.eth2.pid with pid 2217 killed old client process, removed PID file Internet Systems Consortium DHCP Client V3.1.1 Copyright 2004-2008 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ Listening on LPF/eth2/00:40:f4:ba:c4:41 Sending on LPF/eth2/00:40:f4:ba:c4:41 Sending on Socket/fallback DHCPRELEASE on eth2 to 192.168.1.254 port 67 gateway:~# ping google.com PING google.com (66.102.11.104) 56(84) bytes of data. 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=1 ttl=58 time=32.8 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=2 ttl=58 time=32.7 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=3 ttl=58 time=32.9 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=4 ttl=57 time=33.3 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=5 ttl=57 time=32.6 ms ^C --- google.com ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 4017ms rtt min/avg/max/mdev = 32.694/32.923/33.373/0.263 ms gateway:~# ifup eth2 Internet Systems Consortium DHCP Client V3.1.1 Copyright 2004-2008 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ Listening on LPF/eth2/00:40:f4:ba:c4:41 Sending on LPF/eth2/00:40:f4:ba:c4:41 Sending on Socket/fallback DHCPDISCOVER on eth2 to 255.255.255.255 port 67 interval 8 DHCPOFFER from 192.168.1.254 DHCPREQUEST on eth2 to 255.255.255.255 port 67 DHCPACK from 192.168.1.254 bound to 192.168.1.2 -- renewal in 20576 seconds. if-up.d/mountnfs[eth2]: waiting for interface dsl-provider1 before doing NFS mounts (warning). if-up.d/mountnfs[eth2]: waiting for interface dsl-provider before doing NFS mounts (warning). gateway:~# ping google.com PING google.com (66.102.11.104) 56(84) bytes of data. ^C --- google.com ping statistics --- 5 packets transmitted, 0 received, 100% packet loss, time 4013ms gateway:~# ifdown eth3 There is already a pid file /var/run/dhclient.eth3.pid with pid 2523 killed old client process, removed PID file Internet Systems Consortium DHCP Client V3.1.1 Copyright 2004-2008 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ Listening on LPF/eth3/00:60:67:72:40:42 Sending on LPF/eth3/00:60:67:72:40:42 Sending on Socket/fallback DHCPRELEASE on eth3 to 192.168.1.254 port 67 gateway:~# ping google.com ping: unknown host google.com gateway:~# ping 4.2.2.2 connect: Network is unreachable gateway:~# ping 4.2.2.2 connect: Network is unreachable gateway:~# ip route 150.101.180.24 dev ppp0 proto kernel scope link src 150.101.179.XXX 192.168.5.0/24 dev eth1 proto kernel scope link src 192.168.5.254 192.168.1.0/24 dev eth2 proto kernel scope link src 192.168.1.2 gateway:~# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 150.101.180.24 * 255.255.255.255 UH 0 0 0 ppp0 192.168.5.0 * 255.255.255.0 U 0 0 0 eth1 192.168.1.0 * 255.255.255.0 U 0 0 0 eth2 gateway:~# ping google.com ping: unknown host google.com gateway:~# plog Nov 11 17:17:07 gateway pppd[2139]: sendPacket: send: Network is down Nov 11 17:17:07 gateway pppd[2139]: Exit. gateway:~# poff -a gateway:~# pon dsl-provider Plugin rp-pppoe.so loaded. gateway:~# pon dsl-provider1 Plugin rp-pppoe.so loaded. gateway:~# ping google.com PING google.com (66.102.11.104) 56(84) bytes of data. 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=1 ttl=57 time=32.8 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=2 ttl=58 time=32.5 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=3 ttl=57 time=32.9 ms 64 bytes from syd01s01-in-f104.1e100.net (66.102.11.104): icmp_seq=4 ttl=57 time=32.3 ms ^C --- google.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3008ms rtt min/avg/max/mdev = 32.373/32.657/32.906/0.218 ms gateway:~# gateway:~# ip route get 5.5.5.5 5.5.5.5 dev ppp0 src 150.101.179.XXX cache mtu 1492 advmss 1452 hoplimit 64 gateway:~# 
ip link show; ip neigh show; ip route show; ip route get 5.5.5.5;from when both links are up?