Re: Source IPv4 address selection vs BGP IX connection
- In reply to: Gregory Shapiro : "Source IPv4 address selection vs BGP IX connection"
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Date: Wed, 24 Apr 2024 18:05:33 UTC
On 4/23/2024 10:12 PM, Gregory Shapiro wrote: > Short version: > > Using FreeBSD as a BGP router has network issues caused by suboptimal > default IPv4 source address selection when connected to Internet > Exchanges (which are required to use IPs that aren't routable on the > Internet). I was hoping to find more elegant workarounds or encourage > FreeBSD to add source IPv4 selection akin to the existing IPv6 source > address selection (no_prefer_iface and prefer_source). > > I assume that there is a group of BGP enthusiasts using FreeBSD lurking > on freebsd-net. What have you done to solve this problem? > For DNS in such situations I start unbound locally and bind it to an internal interface or an IP on lo0 and then tell unbound to just use that IP only (outgoing-interface IIRC) that is advertised out as a work around. Its not a proper solution, but will get your resolver working at least. I run into this problem in layered networks where the next hop is often RFC 1918 addrs. I bind applications to internal NICs that have addresses that have routing to/from. ---Mike