Sure, WRT54Gs with stock firmware. They have no business running a building @ UCSD though. So this doesn't add up. I'm sure their IT is running some sort of modern-ish gear, all of which supports BGP.
Well I use Dell PowerConnect 64xx as "coreswitch" in the buildings at work and they do Layer 3 "switching" (aka routing), are modern-ish, but they don't speak BGP, only OSPF and RIP. And even they are configured with static routes between the buildings because it are only a few routes.
73s Robbie