Re: : Can a prefix be never routed on Internet but used only for source address in IP packets?

I believe IXP networks are usually like this. Globally assigned IPs, and routers can use their IPs on the network to originate ICMP packets (e.g. TTL exceeded during traceroute; or packet too big)

actually, the inter participant bgp peering (and peering with RSs) is done using TCP over that non-announced address space. randy