Security Basics mailing list archives
RE: Measuring failover time from a link failure
From: "David Gillett" <gillettdavid () fhda edu>
Date: Thu, 20 Dec 2007 09:47:50 -0800
There are at least two different technologies on your list, neither of which necessarily involves anything normally called "failover". An Ethernet trunk uses some form of packet tagging to carry traffic for multiple VLANs over a single physical connection. There is no inherent failover -- if the physical link goes dead, all of the VLANs are disconnected over that link. It is common for trunks to be used in an environment where OSPF or EIGRP or STP will be used to redirect traffic over some redundant physical path, but any or all of those could equally be used in an environment without trunking, so your question should be about them and not about trunking itself. I believe all of the other terms you've used refer to treating a group of parallel connections as a single high-bandwidth link. Obviously any such scheme needs a way to handle outages on individual physical connections within the group, but the rest of the world sees this as fluctuation of the available bandwidth on the aggregated link, and not as failover to a different link. Note that if all the members of the aggregate flow through the same conduit, they can all be severed by a single "backhoe interrupt", requiring failover to an alternate path/route -- see OSPF etc above. David Gillett
-----Original Message----- From: Matthias Merk [mailto:macem99 () gmail com] Sent: Thursday, December 20, 2007 3:06 AM To: security-basics () securityfocus com Subject: Measuring failover time from a link failure Hi I'm about to evaluate some Core Routers (Catalyst/Passport class) so my question is, does anyone know of a tool/script or a method to measure failover times of a "Ethernet trunk", "NIC teaming", "port teaming", "port trunking", "EtherChannel", "Multi-Link Trunking (MLT)" ... whatever you want to call it. Googling for "measuring link failover time" or something like that didnt bring up much good. Thanks in advance! Matthias
Current thread:
- Measuring failover time from a link failure Matthias Merk (Dec 20)
- RE: Measuring failover time from a link failure David Gillett (Dec 20)
- Message not available
- Re: Measuring failover time from a link failure Matthias Merk (Dec 31)