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New Member

Sup IV C4503

Hi,

I'm reading up on the catalyst 4503 with sup IV.

It says it takes 192 000 TCAM entries and then further down it says it supports 131 000 routing entries(shared Multicast/Unicast).My question is will this router be able to peer using BGP and to receive the full internet routing?

7 REPLIES

Re: Sup IV C4503

Hello Tyrone,

I really feel that you should not be going for SUP IV for BGP , with full internet routing.. typically , u can find close to 140 K routes on internet and it might really choke the SUP IV. you need to probably look at a cat 6k with SUP 2 or SUP 720 or look in for routers like 7200... Just check the TCAM/routing table entries before you enable BGP.. 256 K routing entries would be really fine and have no issues.. or you can filter a lot of routes on ur SUP IV and have partial routing tables..... we also need to consider the CPU for this, and cat 6 K has a better CPU than the 4k...

Hope this helps.. all the best.. rate replies if found useful..

Raj

New Member

Re: Sup IV C4503

The latest BGP reports put the global internet routing table, before filtering, at a tad over 200,000 routes. If you run any appreciable-sized IGP then you may hit the unicast limit on the Sup720 before too long.

Thats too many forwarding table entries for a Sup4.

For more information about the state of play in the global BGP table check out the CIDR report at:

http://www.cidr-report.org/

Re: Sup IV C4503

thanks for the info adrian... :)

New Member

Re: Sup IV C4503

Thank you for your replies.

I haven't done the dimensions on this setup, but I must now sort it out using the Sup IV on the 4K.

Anyway if I filter from a /23 I get about 93K routes which is then perfect.

Is there a major problem filtering everything after /23, most operators filter from /24 anyway and all I'll be missing is about 100K routes.

New Member

Re: Sup IV C4503

Hm, I'd be careful - this means you have to run with a default route and you'll want to be absolutely sure the default route pointing to your upstreams depends upon the upstream being being able to carry the traffic!

Ie, if you have two ISPs A and B, and your default points to A, then you're hoping that A will actually be able to reach all the destinations which you're filtering announcements for. There's the possibility that A will suffer a transient failure and not be able to "see" parts of the internet - you'll pass them packets to destinations you don't have a route for (and hence use your default) and the ISP A won't be able to do anything with them.

Another more common issue is your default ISP going away - ie, you default to ISP A, ISP A disappears and BGP detects it, but the link stays up and thus you send all your traffic into a blackhole. There's a couple of ways around this. The easiest way is to use SLA tracking which can be configured to ICMP ping the host every few seconds to see them being up, then make your route dependant upon that monitored object being up.

The feature is called "Reliable Static Routing Backup Using Object Tracking". I have no idea whether its supported on the Catalyst 4500; you'll have to do a little digging.

New Member

Re: Sup IV C4503

Thanks Adrian, I did some digging and hey guess what there's support for "Reliable Static Routing Backup Using Object Tracking" for int latest IOS 12.2(31)SGA for the 45k.

I hear some people talk about using HSRP for this.

What are your thoughts on that?

New Member

Re: Sup IV C4503

What I meant to say is that there is NO support for this faeture in IOS 12.2 for the 45K

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