Comments on: Odd iproute2 gateway behavior with two gateways http://blog.khax.net/2010/01/26/odd-iproute2-gateway-behavior-with-two-gateways/?utm_source=rss&utm_medium=rss&utm_campaign=odd-iproute2-gateway-behavior-with-two-gateways Webdev & Devops Blog Sat, 31 Dec 2011 04:54:04 +0000 hourly 1 By: Jeremy Visser http://blog.khax.net/2010/01/26/odd-iproute2-gateway-behavior-with-two-gateways/#comment-96 Jeremy Visser Tue, 26 Jan 2010 04:02:18 +0000 http://blog.khax.net/?p=169#comment-96 Haven’t done anything with multiple gateways, because despite the ability of Internode to support concurrent PPPoE sessions (up to 4), when you fire up a second DHCPv6 instance, it kills Internode’s route to the first instance. I spose I could use a Hexago tunnel to emulate it, but couldn't really be bothered at this stage. Native IPv6 FTW. Haven’t done anything with multiple gateways, because despite the ability of Internode to support concurrent PPPoE sessions (up to 4), when you fire up a second DHCPv6 instance, it kills Internode’s route to the first instance.

I spose I could use a Hexago tunnel to emulate it, but couldn’t really be bothered at this stage. Native IPv6 FTW.

]]> By: agentk http://blog.khax.net/2010/01/26/odd-iproute2-gateway-behavior-with-two-gateways/#comment-95 agentk Tue, 26 Jan 2010 03:32:17 +0000 http://blog.khax.net/?p=169#comment-95 I'm pretty sure it would work if either eth1 or 2 were in the list on their own, and even with eth1 and 2 in the list as long as eth1 was first. We already had the snat rules setup as as soon as the eth2 default was removed all of the multigateway routing started working too with eth1 and eth2 gateways also in their own connection tables. Interesting point about IPv6 too. I'm using Internode too and have been following your progress with IPv6 and Internode. You havn't tried multigateway connections on IPv6 have you? I’m pretty sure it would work if either eth1 or 2 were in the list on their own, and even with eth1 and 2 in the list as long as eth1 was first.

We already had the snat rules setup as as soon as the eth2 default was removed all of the multigateway routing started working too with eth1 and eth2 gateways also in their own connection tables.

Interesting point about IPv6 too. I’m using Internode too and have been following your progress with IPv6 and Internode. You havn’t tried multigateway connections on IPv6 have you?

]]> By: Jeremy Visser http://blog.khax.net/2010/01/26/odd-iproute2-gateway-behavior-with-two-gateways/#comment-94 Jeremy Visser Tue, 26 Jan 2010 03:03:20 +0000 http://blog.khax.net/?p=169#comment-94 And did removing the eth1 route cause the eth2 route to start working (i.e. vice versa)? It's possible the source IP address was wrong, and going via the wrong interface, and thus being filtered at the ISP's end. <code>tcpdump</code> can help you confirm this. What I mean is that if they are separate Internet connections, and you haven't entered any arrangement with the ISP, or the connections are going to separate ISPs, the IP addresses may not be interchangeable. I encountered a similar issue to what I'm describing to you just the other day, except with IPv6. What was happening was that my irssi client running on my router was attempting to connect to IRC with a source IP of <code>::1</code> (the equivalent of 127.0.0.1 in IPv6), instead of the proper IP address on the connecting interface, which was supposed to be <code>2001:44b8:7df3:b970::14</code>. I had to type “<code>/connect -host 2001:44b8:7df3:b970::14 irc.ipv6.freenode.net</code>” inside irssi to force it to connect with the right source address. And did removing the eth1 route cause the eth2 route to start working (i.e. vice versa)?

It’s possible the source IP address was wrong, and going via the wrong interface, and thus being filtered at the ISP’s end. tcpdump can help you confirm this.

What I mean is that if they are separate Internet connections, and you haven’t entered any arrangement with the ISP, or the connections are going to separate ISPs, the IP addresses may not be interchangeable.

I encountered a similar issue to what I’m describing to you just the other day, except with IPv6. What was happening was that my irssi client running on my router was attempting to connect to IRC with a source IP of ::1 (the equivalent of 127.0.0.1 in IPv6), instead of the proper IP address on the connecting interface, which was supposed to be 2001:44b8:7df3:b970::14. I had to type “/connect -host 2001:44b8:7df3:b970::14 irc.ipv6.freenode.net” inside irssi to force it to connect with the right source address.

]]>