nanog mailing list archives
RE: Rapidly-variable routing on the time scale of seconds to minutes?
From: "Charles Shen" <charles () cs columbia edu>
Date: Mon, 31 Jan 2005 22:17:20 -0500
On Mon, Jan 31, 2005 at 09:59:39PM -0500, Charles Shen wrote: [ snip ]From the responses, the answer to "the rapidly-variable routing on the timescale of seconds to minutes" seems to be: 1. It could be link layer load balancing, with the two interfaces belonging to the same router. 2. It could be per-flow loadbalancingwhere flows are defined via both L3 and L4 info, sotraceroute probecould not reflect the truth. My question is then: would it be safe to argue that the above two causes explain all (or most of?) the observed "fluttering" routers? (some examples listed below) What we are concerned about is per-packet load balancing (packets in the same flow go through different paths), which will cause trouble to protocolsthat installstate information in routers along the flow path.AFAIK, multiple routers showing up in a single-hop in traceroute response is a sign of packet-by-packet load balancing, not flow based. I could be wrong, though this was my past observation. P.S.: What router-interacting applications are you using?
I am talking about e.g. QoS reservation signaling applications.
Current thread:
- RE: Rapidly-variable routing on the time scale of seconds to minutes? Charles Shen (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? James (Jan 31)
- RE: Rapidly-variable routing on the time scale of seconds to minutes? Charles Shen (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? John Fraizer (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? Daniel Roesen (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? Daniel Roesen (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? Daniel Roesen (Jan 31)
- Re: Rapidly-variable routing on the time scale of seconds to minutes? James (Jan 31)