Re: [Babel-users] v4-via-v6 and the IPv4 Dummy Address
Juliusz Chroboczek writes: > Hi, > > After I release v4-via-v6, I'll start working on merging HMAC and > v4-via-v6 into babeld. A v4-via-v6 router needs to be able to send ICMPv4 > packets even if it hasn't been allocated an IPv4 address; the simplest way > to achieve that is to use the "IPv4 dummy address". > > https://tools.ietf.org/html/draft-ietf-babel-v4viav6-03#section-3 > > Question: how do we achieve this? The best solution would be to modify > the Linux kernel to use the dummy address for sending ICMPv4 when it has > no IPv4 addresses available. The second best would be to automatically > add the IPv4 dummy address to the loopback interface when Babeld > starts. What does the kernel do currently? And will setting an address on the loopback interface help at all? The documentation for the icmp_errors_use_inbound_ifaddr sysctl[0] says this: Note that if no primary address exists for the interface selected, then the primary address of the first non-loopback interface that has one will be used regardless of this setting. -Toke [0] In https://www.kernel.org/doc/html/latest/networking/ip-sysctl.html ___ Babel-users mailing list Babel-users@alioth-lists.debian.net https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
Re: [Babel-users] v4-via-v6 and the IPv4 Dummy Address
> What does the kernel do currently? I don't know. Théo was supposed to do some tests, but then he decided he's more interested in other stuff. We need to test. > And will setting an address on the loopback interface help at all? The > documentation for the icmp_errors_use_inbound_ifaddr sysctl[0] says > this: > Note that if no primary address exists for the interface selected, > then the primary address of the first non-loopback interface that has > one will be used regardless of this setting. That looks bad. Thanks for the pointer. -- Juliusz ___ Babel-users mailing list Babel-users@alioth-lists.debian.net https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
[Babel-users] v4-via-v6 and the IPv4 Dummy Address
Hi, After I release v4-via-v6, I'll start working on merging HMAC and v4-via-v6 into babeld. A v4-via-v6 router needs to be able to send ICMPv4 packets even if it hasn't been allocated an IPv4 address; the simplest way to achieve that is to use the "IPv4 dummy address". https://tools.ietf.org/html/draft-ietf-babel-v4viav6-03#section-3 Question: how do we achieve this? The best solution would be to modify the Linux kernel to use the dummy address for sending ICMPv4 when it has no IPv4 addresses available. The second best would be to automatically add the IPv4 dummy address to the loopback interface when Babeld starts. Ideas? -- Juliusz ___ Babel-users mailing list Babel-users@alioth-lists.debian.net https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
