Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
On Mon, 9 Jun 2014, John van Oppen wrote: It is generally much better to do the following: mls cef maximum-routes ipv6 90 mls cef maximum-routes ip-multicast 1 This will leave v4 and mpls in one big pool, puts v6 to something useful for quite a while and steals all of the multicast space which is not really used on most deployments. This gives us the following (which is pretty great for IP backbone purposes in dual stack): #show mls cef maximum-routes FIB TCAM maximum routes : === Current :- --- IPv4 + MPLS - 832k (default) IPv6- 90k IP multicast- 1k I was just looking at / thinking about this again, and though I don't disagree that doing the split your way is probably better, I think it's a moot point. I strongly suspect these boxes will run out of RAM before they're able to utilize another 256k routing slots with multiple full v4 tables. -- Jon Lewis, MCP :) | I route | therefore you are _ http://www.lewis.org/~jlewis/pgp for PGP public key_
Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
On 13/06/2014 15:54, Jon Lewis wrote: I was just looking at / thinking about this again, and though I don't disagree that doing the split your way is probably better, I think it's a moot point. I strongly suspect these boxes will run out of RAM before they're able to utilize another 256k routing slots with multiple full v4 tables. to a certain extent that depends on what software you're using. 12.x seems to be a good bit more memory efficient than 15.x on the sup720. Otherwise yeah, RP memory is the next critical limiting factor on these boxes, assuming if you can live with the crippling convergence times with large numbers of prefixes. Nick
Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
John, great point! Regardless, shouldn't need more than 626K to make it to v6 and we wont need as many for v6. That was one of the problems that v6 was designed to address. On Mon, Jun 9, 2014 at 1:27 PM, John van Oppen jvanop...@spectrumnet.us wrote: It is generally much better to do the following: mls cef maximum-routes ipv6 90 mls cef maximum-routes ip-multicast 1 This will leave v4 and mpls in one big pool, puts v6 to something useful for quite a while and steals all of the multicast space which is not really used on most deployments. This gives us the following (which is pretty great for IP backbone purposes in dual stack): #show mls cef maximum-routes FIB TCAM maximum routes : === Current :- --- IPv4 + MPLS - 832k (default) IPv6- 90k IP multicast- 1k John -Original Message- From: NANOG [mailto:nanog-boun...@nanog.org] On Behalf Of Jon Lewis Sent: Monday, June 09, 2014 12:10 PM To: Pete Lumbis Cc: nanog@nanog.org Subject: Re: Getting pretty close to default IPv4 route maximum for 6500/7600routers. Why, in your example, do you bias the split so heavily toward IPv4 that the router won't be able to handle a current full v6 table? I've been using mls cef maximum-routes ip 768 which is probably still a little too liberal for IPv6 FIB TCAM maximum routes : === Current :- --- IPv4- 768k MPLS- 16k (default) IPv6 + IP Multicast - 120k (default) given that a full v6 table is around 17k routes today. A more important question though is how many 6500/7600 routers will fully survive the reload required to affect this change? I've lost a blade (presumably to the bad memory issue) each time I've rebooted a 6500 to apply this. On Mon, 9 Jun 2014, Pete Lumbis wrote: The doc on how to adjust the 6500/7600 TCAM space was just published. http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-serie s-switches/117712-problemsolution-cat6500-00.html On Tue, May 6, 2014 at 3:48 PM, Pete Lumbis alum...@gmail.com wrote: There is currently a doc for the ASR9k. We're working on getting on for 6500 as well. http://www.cisco.com/c/en/us/support/docs/routers/asr-9000-series-agg regation-services-routers/116999-problem-line-card-00.html On Tue, May 6, 2014 at 1:34 PM, bedard.p...@gmail.com wrote: I would like to see Cisco send something out... -Original Message- From: Drew Weaver drew.wea...@thenap.com Sent: ÿÿ5/ÿÿ6/ÿÿ2014 11:42 AM To: 'nanog@nanog.org' nanog@nanog.org Subject: Getting pretty close to default IPv4 route maximum for 6500/7600routers. Hi all, I am wondering if maybe we should make some kind of concerted effort to remind folks about the IPv4 routing table inching closer and closer to the 512K route mark. We are at about 94/95% right now of 512K. For most of us, the 512K route mark is arbitrary but for a lot of folks who may still be running 6500/7600 or other routers which are by default configured to crash and burn after 512K routes; it may be a valuable public service. Even if you don't have this scenario in your network today; chances are you connect to someone who connects to someone who connects to someone (etc...) that does. In case anyone wants to check on a 6500, you can run: show platform hardware capacity pfc and then look under L3 Forwarding Resources. Just something to think about before it becomes a story the community talks about for the next decade. -Drew -- Jon Lewis, MCP :) | I route | therefore you are _ http://www.lewis.org/~jlewis/pgp for PGP public key_ -- eSited LLC (701) 390-9638
RE: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
Yep, exactly… the problem is the carving suggested by most kills the fact that MPLS and v4 are pooled, which on a larger network is very nice, especially if using 6PE where each v6 route may need an MPLS route too. From: Bryan Tong [mailto:cont...@nullivex.com] Sent: Monday, June 09, 2014 12:37 PM To: John van Oppen Cc: nanog@nanog.org Subject: Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers. John, great point! Regardless, shouldn't need more than 626K to make it to v6 and we wont need as many for v6. That was one of the problems that v6 was designed to address. On Mon, Jun 9, 2014 at 1:27 PM, John van Oppen jvanop...@spectrumnet.usmailto:jvanop...@spectrumnet.us wrote: It is generally much better to do the following: mls cef maximum-routes ipv6 90 mls cef maximum-routes ip-multicast 1 This will leave v4 and mpls in one big pool, puts v6 to something useful for quite a while and steals all of the multicast space which is not really used on most deployments. This gives us the following (which is pretty great for IP backbone purposes in dual stack): #show mls cef maximum-routes FIB TCAM maximum routes : === Current :- --- IPv4 + MPLS - 832k (default) IPv6- 90k IP multicast- 1k John -Original Message- From: NANOG [mailto:nanog-boun...@nanog.orgmailto:nanog-boun...@nanog.org] On Behalf Of Jon Lewis Sent: Monday, June 09, 2014 12:10 PM To: Pete Lumbis Cc: nanog@nanog.orgmailto:nanog@nanog.org Subject: Re: Getting pretty close to default IPv4 route maximum for 6500/7600routers. Why, in your example, do you bias the split so heavily toward IPv4 that the router won't be able to handle a current full v6 table? I've been using mls cef maximum-routes ip 768 which is probably still a little too liberal for IPv6 FIB TCAM maximum routes : === Current :- --- IPv4- 768k MPLS- 16k (default) IPv6 + IP Multicast - 120k (default) given that a full v6 table is around 17k routes today. A more important question though is how many 6500/7600 routers will fully survive the reload required to affect this change? I've lost a blade (presumably to the bad memory issue) each time I've rebooted a 6500 to apply this. On Mon, 9 Jun 2014, Pete Lumbis wrote: The doc on how to adjust the 6500/7600 TCAM space was just published. http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-serie s-switches/117712-problemsolution-cat6500-00.html On Tue, May 6, 2014 at 3:48 PM, Pete Lumbis alum...@gmail.commailto:alum...@gmail.com wrote: There is currently a doc for the ASR9k. We're working on getting on for 6500 as well. http://www.cisco.com/c/en/us/support/docs/routers/asr-9000-series-agg regation-services-routers/116999-problem-line-card-00.html On Tue, May 6, 2014 at 1:34 PM, bedard.p...@gmail.commailto:bedard.p...@gmail.com wrote: I would like to see Cisco send something out... -Original Message- From: Drew Weaver drew.wea...@thenap.commailto:drew.wea...@thenap.com Sent: ÿÿ5/ÿÿ6/ÿÿ2014 11:42 AM To: 'nanog@nanog.orgmailto:nanog@nanog.org' nanog@nanog.orgmailto:nanog@nanog.org Subject: Getting pretty close to default IPv4 route maximum for 6500/7600routers. Hi all, I am wondering if maybe we should make some kind of concerted effort to remind folks about the IPv4 routing table inching closer and closer to the 512K route mark. We are at about 94/95% right now of 512K. For most of us, the 512K route mark is arbitrary but for a lot of folks who may still be running 6500/7600 or other routers which are by default configured to crash and burn after 512K routes; it may be a valuable public service. Even if you don't have this scenario in your network today; chances are you connect to someone who connects to someone who connects to someone (etc...) that does. In case anyone wants to check on a 6500, you can run: show platform hardware capacity pfc and then look under L3 Forwarding Resources. Just something to think about before it becomes a story the community talks about for the next decade. -Drew -- Jon Lewis, MCP :) | I route | therefore you are _ http://www.lewis.org/~jlewis/pgp for PGP public key_ -- eSited LLC (701) 390-9638
Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
I botched those numbers. Let me fix. According to this countdown: http://inetcore.com/project/ipv4ec/index_en.html we have 6.41 /8's left. So that is 107,541,955 IPs. CIDR - Prefixes - /20 - 26,255.36 /21 - 52,510.72 /22 - 105,021.44 /23 - 210,042.88 /24 - 420,085.76 My apologies for my erroneous math, I was off one number making the table. Johns solution to combine MPLS and IPv4 is the best solution. I would implement it if I hadn't already rebooted a few days ago.
Re: FW: Getting pretty close to default IPv4 route maximum for 6500/7600routers.
Even if the first numbers were correctly calculated, they don't allow for further deaggregation of already advertised prefixes, which shouldn't be underestimated as the commercial value of each address increases... On 10.06.2014 06:17, Bryan Tong wrote: I botched those numbers. Let me fix. According to this countdown: http://inetcore.com/project/ipv4ec/index_en.html we have 6.41 /8's left. So that is 107,541,955 IPs. CIDR - Prefixes - /20 - 26,255.36 /21 - 52,510.72 /22 - 105,021.44 /23 - 210,042.88 /24 - 420,085.76 My apologies for my erroneous math, I was off one number making the table. Johns solution to combine MPLS and IPv4 is the best solution. I would implement it if I hadn't already rebooted a few days ago.
