nanog mailing list archives
Re: Using IPv6 with prefixes shorter than a /64 on a LAN
From: Per Carlson <pelle () hemmop com>
Date: Mon, 31 Jan 2011 12:27:43 +0100
At AMSIX, a Cisco 12000 running IOS will get into trouble with the 170pps of ND seen there. AMSIX doesn't do MLD snooping so everybody gets everything and on IOS 12000 ND is punted to RP and when it's busy with calculating BGP, it'll start dropping BGP sessions.
Really? I've tried to duplicate the results in our lab, but I can't provoke any problems at those numbers. Is it the "other" multicast traffic that's interfering with ND? When pounding the CPU with ~30 times more (5000pps) Neighbour solicitations and flapping 1000 BGP IPv4 prefixes (out of 51000) every 5 seconds, I get the following load (worst case): 12k#sh proc cpu | ex 0.00 CPU utilization for five seconds: 99%/13%; one minute: 83%; five minutes: 76% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process 29 19472 7944653 2 0.31% 0.07% 0.05% 0 PowerMgr Main 160 5120 3415 1499 0.47% 0.18% 0.06% 0 Exec 181 17016 76522129 0 0.07% 0.14% 0.15% 0 CEF RP IPC Backg 185 1992892 19727573 101 17.91% 19.36% 20.02% 0 IPv6 Input 213 256008 9155905 27 3.03% 2.80% 2.83% 0 BGP Router 216 3606044 677600 5321 64.31% 45.74% 37.41% 0 BGP Scanner 12k# Even though the load is high, there is no flaps, neither in ISIS, LDP, BFD (3 sessions with 3 x 50 ms asynch mode) nor BGP. When BGP Scanner is not running, the numbers are much lower: martin#sh proc cpu | ex 0.00 CPU utilization for five seconds: 45%/16%; one minute: 82%; five minutes: 76% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process 160 5192 3454 1503 0.79% 0.20% 0.08% 0 Exec 181 17068 76522593 0 0.15% 0.15% 0.15% 0 CEF RP IPC Backg 185 2000528 19764701 101 24.79% 19.70% 20.01% 0 IPv6 Input 213 256976 9156110 28 3.03% 2.82% 2.83% 0 BGP Router martin# The hardware in question is a PRP-1 running SY9b, and the same LC (SIP-601/SPA-5x1GE-v2) is used for both ND and BGP. Note: When doing 10000pps ND, the LDP-adjacency with a neighbour on the same LC did flap occasionally. -- Pelle RFC1925, truth 11: Every old idea will be proposed again with a different name and a different presentation, regardless of whether it works.
Current thread:
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN, (continued)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Michael Dillon (Jan 31)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Owen DeLong (Jan 31)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Owen DeLong (Jan 25)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Ray Soucy (Jan 26)
- RE: Using IPv6 with prefixes shorter than a /64 on a LAN George Bonser (Jan 25)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Fernando Gont (Jan 25)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Matthew Petach (Jan 30)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Fernando Gont (Jan 30)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Matthew Petach (Jan 31)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Mikael Abrahamsson (Jan 30)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Per Carlson (Jan 31)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Mikael Abrahamsson (Jan 31)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Mark Andrews (Jan 24)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Owen DeLong (Jan 24)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN sthaug (Jan 24)
- Re: Using IPv6 with prefixes shorter than a /64 on a LAN Mark Smith (Jan 25)