Re:Hello IPv6: a minimal tutorial for IPv4 users
by Dylan16807 on Thursday October 07, 2021 @07:38PM
(#28793596)
I know routing table bloat is annoying and it's hard to do tons of routes in an ultra-fast way, but I do want to point out that "millions and millions of routes" translates to "tens and tens of megabytes".
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Re:Hello IPv6: a minimal tutorial for IPv4 users
by Dagger2 on Saturday October 09, 2021 @12:14AM
(#28807002)
But if you're doing fast hardware routing, that's tens and tens of megabytes of TCAM, not DRAM. It's more akin to CPU cache in terms of latency, capacity and cost.
Re:Hello IPv6: a minimal tutorial for IPv4 users
by Dylan16807 on Saturday October 09, 2021 @12:45AM
(#28807131)
You can get a $600 Epyc with 128MB of cache. That shouldn't be too much compared to the tier of router we're talking about, right?
Re:Hello IPv6: a minimal tutorial for IPv4 users
by Dagger2 on Saturday October 09, 2021 @02:01AM
(#28807418)
That's L3 cache though; they only have 0.5 MB of L2 cache per core.
I'm not really sure how much each of these types of memory cost, but I did find [1] which says "The cost of TCAM is also about 30 times more per bit of storage than SRAM". That suggests a CPU with something more like 0.5-1 GB of L3 cache would be a closer comparison.
[1] https://research.ijcaonline.org/volume115/number7/pxc3902299...