5 ms·
If google advertised several /24 for these ip networks instead of /19, this would have not happenned.
by john37386 8y ago
If google advertised several /24 for these ip networks instead of /19, this would have not happenned.
- tyingq 8y agoIs that a best practice though? Wouldn't the BGP tables get pretty big if everyone did that?
- ahmedalsudani 8y agoThey would, and we would probably see a repeat of this: https://bgpmon.net/what-caused-todays-internet-hiccup/ https://bgpmon.net/what-caused-todays-internet-hiccup/
- apathy 8y agoUgh, old Cisco trash Didn’t Pakistan advertise a /28 at one point that blackholed YouTube? Good times. (/s)
- tyingq 8y agoI believe there are routers that break at around 1M ipv4 entries, and we're at ~700k now. https://www.cidr-report.org/cgi-bin/plota?file=%2fvar%2fdata%2fbgp%2fas2.0%2fbgp-active%2etxt&descr=Active%20BGP%20entries%20%28FIB%29&ylabel=Active%20BGP%20entries%20%28FIB%29&with=step https://www.cidr-report.org/cgi-bin/plota?file=%2fvar%2fdata...
- baseballMan 8y agoWow - it's really gone up in the last couple of years. I think it was at 550k last time I had access to an edge router.
- Hikikomori 8y agoNow that other ISP would advertise Googles /24's, it doesn't help.
- zaroth 8y agoAdvertising every /24 within a /19 - would that take exactly 32 route advertisements?
- sathackr 8y agoYou are correct. 24-19 = 5 bits. 2^5 = 32
- sathackr 8y agoAnd if everyone advertised /24s instead of larger aggregate networks, routers would have to store about 12 million routes. Better yet, why not just advertise a /32 for every IP address? Most routers would crash and the internet would stop long before we ever got to 12 million routes.
- jarfil 8y agoThat's a lot of words to say that BGP is outdated.
- noselasd 8y agoHow would an alternative deal with that problem ?
- john37386 8y agoSome /24 are more critical than other. There is a price to security and for sure advertising only /24 is probably not viable. The article mentionned that some networks within the /19, in this incident, were critical. So yes, I believe that every businesses should advertise /24 for their highly critical infra. They can advertise /19, /20 and so on for the less important networks. No need to use /24 for everything.
- sathackr 8y agoA valid point that I thought you might have meant after re-reading your post a couple of times. Sorry for the quick-fire snark.
- gcbirzan 8y agoIt would have happened, and not even doing it as a mitigation would've worked, as the offending ISP would've re-advertised the same routes as google shortly after google changed it.