Use of BGP on Switch WS-C3750X-48T-E

[Garry Kabbay]

Hi Expert

I need your expert suggestion regarding use the  WS-C3750X-48T-E (License : ipservices) switches for eBGP.

Can this switch handle eBGP, interms of memory Space for BGP table and any other performance issue will rise. As these switches we normally use for LAN switching. Currently we are using EIGRP protocol on it for MAN connectivity to other location and we want to migrate from EIGRP to eBGP.

please suggest if this switch is good for eBGP and there will be no performance issue.

Regards

[MHM Cisco World · Accepted solution]

if you receive default route then this SW is OK if full bgp Table then you must check the memory.

[M02@rt37 · Accepted solution]

Hello @Garry Kabbay,

The WS-C3750X-48T-E is primarily designed for LAN switching and has limited hardware resources compared to dedicated routers. It has a smaller routing table capacity compared to high-end routers typically used for Internet edge routing. The exact routing table capacity can vary depending on factors such as the number of routes, memory allocation, and the version of Cisco IOS software running on the switch.

For small-scale deployments or scenarios with limited BGP routing table sizes, the WS-C3750X-48T-E can function adequately as an eBGP router. However, for larger-scale deployments or scenarios with a substantial BGP routing table, it is advisable to consider dedicated routers.

[Garry Kabbay]

Thanks for your Guidance.

[Joseph W. Doherty]

Overlapping with prior replies . . .

"Can this switch handle eBGP"

Believe so.

"interms of memory Space for BGP table"

Depends on the size of the BGP table.  If you're thinking full Internet BGP - noooo!!!

"any other performance issue will rise."

Possibly.  Depending on what you're doing, you might run out of TCAM resources for dealing with a large route table before you actually run of of RAM to contain it.  If this happens, switch might still continue to function, but doing some of its processing without TCAM support.  If that happens, performance can go from wire-rate/line-speed to abysmal.

"Currently we are using EIGRP protocol on it for MAN connectivity to other location and we want to migrate from EIGRP to eBGP."

It might work find using BGP vs. EIGRP, but even if that's true, actual migration might have issues as, I assume, for some period there would be a need to run both routing protocols, concurrently.

"As these switches we normally use for LAN switching."

Indeed they are.  If fact, even for that role, they often come up short if used as a core or distribution layer device.  They also run into performance issues (lack of port buffer resources) as edge devices, if they are handling much traffic (like servers, rather than users).  (For non-user edge roles, the [EoL] 4948 switch was a much better choice.)

For MAN networks, Cisco (at least the used to - still?) also has a line of switches, with additional hardware resources, that serve the MAN role better, but they too (usually) don't have the resources for dealing with a full Internet route table.

Again, not knowing more specifics, your 3750-Xs might be fine; just be prepared for issues, especially during conversion.

BTW, you can monitor RAM and/or TCAM usage, including now, to provide you available resource levels.