As noted in this thread on the quagga users mailing list [1], there is a severe memory leak in quagga that consumes a lot of memory very quickly.  According to the list messages, it was introduced in 0.99.19 and is not yet fixed, although a patch was posted [2] that looks to have solved the problem.

We may want to patch quagga now (I see 0.99.20 in -testing) to prevent users having to suffer through major memory problems.

[1] http://lists.quagga.net/pipermail/quagga-users/2011-October/012529.html
[2] http://patchwork.diac24.net/patch/402/

(As an aside, this came to us as a possible security flaw, but I think this should be classified more as a really bad bug than a security flaw since just starting quagga is causing the problem).

Perhaps it is doable to respin the 0.99.20 packages in -testing to get this patch included?  Thanks!