By TTL expiry I didn't mean change TTL expiry behavior. I meant set TT=1 for first DP packet then set TTL=2 for 2nd DP packet and so forth. And for each TTL just one router that detects TTL expiry will respond.
Regards, Shahram On Nov 4, 2015, at 11:47 AM, Dapeng Liu <[email protected]<mailto:[email protected]>> wrote: 2015-11-04 10:29 GMT+08:00 Sam Aldrin <[email protected]<mailto:[email protected]>>: I expressed the same concern at last IETF meeting, as Shahram raised here. Haven’t gotten the explanation yet. If TTL expiry mechanism is used, then the definition of IP TTL will have to be redefined in order to make a copy and forward to next hop. But if L3 devices have to read into VXLAN header to determine OAM bit is set, they need to implement DPI for the same. As respond to Shahram's question, there are various ways to implement this. ACL etc.. Secondly, imagine when there exists a loop. In fact, they do exist even in controller based networks. The PD packet has TTL also to avoid this. Speaking as an operator, as mentioned yesterday, this will cause packet storm and unintended consequences. We are also operator, we do not see problems here. Maybe we need more clarification and offline discussion to make sure our solution be understood correctly. Thanks for the comments, Dapeng Liu Why are we solving the problem when it doesn’t exist? -sam On Nov 3, 2015, at 6:02 PM, Shahram Davari <[email protected]<mailto:[email protected]>> wrote: I think your assumption is broken. But you have an alternative method and that is using TTL expiry. Thx SD From: Dacheng Zhang [mailto:[email protected]] Sent: Tuesday, November 03, 2015 5:53 PM To: Shahram Davari; [email protected]<mailto:[email protected]> Subject: Re: [nvo3] draft--pang--nvo3--vxlan--path--detection--01 This draft actually proposes a mechanism where the intermediates are required to recognize the vxlan oam packets. If this assumption is broken, the solutions proposed in this draft may not be effective. Cheers Dacheng 发件人: nvo3 <[email protected]<mailto:[email protected]>> on behalf of Shahram Davari <[email protected]<mailto:[email protected]>> 日期: 2015年11月4日 星期三 上午9:33 至: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> 主题: [nvo3] draft-‐pang-‐nvo3-‐vxlan-‐path-‐detection-‐01 Hi, This draft needs to address how intermediate L3 routers are going to see these VXLAN OAM packets, since L3 routers just do L3 routing and don’t look at the payload to see it is VXLAN and then see that these are PD OAM packets. The only option I can think of is TTL expiry, otherwise it won’t work, the way it is defined now, Thx Shahram _______________________________________________ nvo3 mailing list [email protected]<mailto:[email protected]>https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/nvo3 -- ------ Best Regards, Dapeng Liu
_______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
