28 Dec
2011
28 Dec
'11
2:41 p.m.
Most vendors have a TCAM that by default does IPv6 routing for netmasks <=64.
They have a separate TCAM (which is usually limited in size) that does routing for masks >64 and <=128.
Please provide references. I haven't seen any documentation of such an architecture myself.
TCAMs are expensive and increase the BOM cost of routers. Storing routes with masks > 64 takes up twice the number of TCAM entries as the routes with masks <= 64. Since IPv6 is *supposed* to work with /64 masks, most vendors (usually the not-so-expensive-routers) provide a smaller TCAM for > /64 masks.
Ah, but do the "not-so-expensive-routers" use TCAM at all? Steinar Haug, Nethelp consulting, sthaug@nethelp.no