[c-nsp] SLA tracking, what do you ping?

[David Freedman]

Jay Nakamura wrote:
> When you use IP SLA to track if an upstream is working on a ISP
> connection (From customer point of view, and you are not the ISP that
> knows what will be safe to ping), what do you usually configure to
> ping?  I have found that one hop up from the CPE is not necessary
> reliable on DSL/Cable.  I was wondering if anyone can share their
> experience on what works well and what to look out for.

Dont know about your ISP , but we provide customers with an anycasted
"sponge" which accepts ICMP and various other standard RTR operations,
for this purpose.

We deployed this mainly as an alternative to running routing protocols
over customer circuits over which there was no link loss detected when a
break in the middle (mainly badly setup 3rd party pseudowire circuits),
am now looking at BFD backed up static routes to replace this.

Routing protocols are always preferable, IMHO.

Dave.

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David Freedman
Group Network Engineering
Claranet Group