On Monday, November 24, 2014 10:08:11 PM Chris Costa wrote:
Is there a BCOP (or substantiated opinion) for negotiating eBGP Graceful-Restart and Graceful-Restart Helper-Mode with external networks? Implementation looks varied across a few larger transit providers, and in some cases implemented inconsistently within the same provider. Seeing most IX peers with GR disabled, although I don't see they've disabled GR Helper Mode. Apparently, Junos (12.3, at least) doesn't offer disabling GR Helper Mode for BGP.
We generally disable GR on eBGP sessions because different peers (be they customers, upstreams or peers) have different hardware/software that could make this tricky. Internally, we run NSR on boxes with dual control planes. This is recent, as several of your garden-variety (and exotic) service provider network protocols and services are now reasonably supported that it makes sense to migrate from GR to NSR. We don't generally run GR on boxes with single control planes, as there could be operational impact when BFD is involved under some circumstances. That said, GR Helper mode tends to always be available even when GR is not enabled. Mark.