RA Guard on Insinuator.net - Bold Statements

RA Guard (Evasion) – We Stand Corrected

Mon, 20 May 2013 00:00:00 +0000

Recently Jozef Pivarník and Matěj Grégr published an excellent write-up on RA Guard & evasion techniques. Amongst others they tested the “undetermined-transport” ACL we described here and here. As it turns out the “workaround” for implementing undetermined-transport on platforms seemingly not supporting it, causes some bad collateral damage: the respective port does not forward any IPv6 packets any more (this was brought to my attention by Roberto Taccon). We had done some tests after applying it (by means of the “workaround”) but we had just looked at fragmented RA packets (which did not get through => test succeeded). So, frankly: the undetermined-transport trick does not make sense at all on the “unsupported platforms”…

RA Guard Support

Thu, 02 May 2013 00:00:00 +0000

Hi,

on the [ipv6-ops] mailing list currently there’s some discussion about RA guard support on switches from different vendors.

Stefan, one of our students (btw: working on a topic similar to this session), quickly put together a preliminary list, based on publicly available information (read: the WWW ;-)). Some of you may find this useful; it can be found here. Furthermore on the list this link was mentioned which seems to provide some info as well (albeit potentially not very up-to-date).

Some more Notes on RA Guard Evasion and “undetermined-transport”

Sat, 13 Apr 2013 00:00:00 +0000

I just had an interesting discussion with Jim Small (who gives the “IPv6 Attacks and Countermeasures” talk at the North American IPv6 Summit next week) about the feasibility of the “undetermined-transport” keyword in PACLs on Cisco 3560 switches (here running IOS 15.0(2)SE). Actually there’s some kind-of funny behavior as for it on that platform (and there’s even some Cisco documentation stating it’s not supported). Let’s have a look, and start with a quick refresher.