nanog mailing list archives
Re: Internet diameter?
From: "tim () pelican org" <tim () pelican org>
Date: Thu, 22 Nov 2018 09:55:47 -0000 (GMT)
On Thursday, 22 November, 2018 05:30, "William Herrin" <bill () herrin us> said:
Good question! It matters because a little over two decades ago we had some angst as equipment configured to emit a TTL of 32 stopped being able to reach everybody. Today we have a lot of equipment configured to emit a TTL of 64. It's the default in Linux, for example. Are we getting close to the limit where that will cause problems? How close?
If it's hop-count that's interesting, I think that raises a question on the potential for a sudden large change in the answer, potentially with unforeseen consequences if we do have a lot of devices with TTL=64. Imagine a "tier-1" carrying some non-trivial fraction of Internet traffic who is label-switching global table, with no TTL-propagation into MPLS, and so looks like a single layer-3 hop today. In response to traceroute-whingeing, they turn on TTL-propagation, and suddenly look like 10 layer-3 hops. Having been in the show/hide MPLS hops internal debate at more than one employer, I'd expect flipping the switch to "show" to generate a certain support load from people complaining that they are now "more hops" away from something they care about (although RTT, packet-loss, throughput remain exactly the same). I wouldn't have expected to break connectivity for a whole class of devices. Regards, Tim.
Current thread:
- Re: Internet diameter?, (continued)
- Re: Internet diameter? Aaron1 (Nov 21)
- Re: Internet diameter? Ross Tajvar (Nov 21)
- Re: Internet diameter? Stephen Satchell (Nov 21)
- Re: Internet diameter? Aaron1 (Nov 21)
- Re: Internet diameter? Christopher Morrow (Nov 21)
- Re: Internet diameter? Bryce Wilson (Nov 21)
- Re: Internet diameter? Ben Cannon (Nov 21)
- Re: Internet diameter? Ross Tajvar (Nov 21)
- Re: Internet diameter? Ross Tajvar (Nov 21)
- Re: Internet diameter? William Herrin (Nov 21)
- Re: Internet diameter? Oliver O'Boyle (Nov 21)
- Re: Internet diameter? tim () pelican org (Nov 22)
- Re: Internet diameter? Lars Prehn (Nov 26)
- Re: Internet diameter? Aaron1 (Nov 21)
- Re: Internet diameter? Christopher Morrow (Nov 23)
- RE: Internet diameter? Keith Medcalf (Nov 22)
- Re: Internet diameter? Mike Hammett (Nov 22)
- RE: Internet diameter? Keith Medcalf (Nov 22)
- RE: Internet diameter? Hal Murray (Nov 24)
- Re: Internet diameter? Christopher Morrow (Nov 25)
- Re: Internet diameter? Casey Russell (Nov 26)
- Re: Internet diameter? Ignacio de castro (Nov 26)
- Re: Internet diameter? Andy Ringsmuth (Nov 21)