Hi all, I notice below description in user guide, my understand is source address mainly used for BGP session for TCP connection ,don't understand why this source is also used as next_hop_addr calculation. If source address is related with next hop calculation, this case is may not support: used MP_REACH_NLRI to support IPV4 route with IPV4 next hop ,but TCP connection type is IPV6. Since to support MP_REACH_NLRI for ipv4 channel, need to enabled ext_next_hop, if enabled ext_next_hop, if ipv6 source address is selected as next_hop_addr if no others configuration for next_hop_addr. Does my understand is correct ? source address ip Define local address we should use for next hop calculation and as a source address for the BGP session. Default: the address of the local end of the interface our neighbor is connected to. Thanks Arvin
On Wed, May 09, 2018 at 07:38:31AM +0000, Arvin Gan wrote:
Hi all,
I notice below description in user guide, my understand is source address mainly used for BGP session for TCP connection ,don't understand why this source is also used as next_hop_addr calculation.
Hi Generally, BGP speaker have to select reasonable bgp_next_hop address from its IP addresses. BIRD uses by default the source address of BGP session if applicable (like matching AF or ext_next_hop), otherwise it takes preferred IPv4 or IPv6 address of the same iface where is the source address. Or could be explicitly configured by 'next hop address' option. See function bgp_channel_start() for details. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."
participants (2)
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Arvin Gan -
Ondrej Zajicek