<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div><div>I understand what you are saying but they are insisting that they router doesnt support 4byte ASN. Im not sure what the router and the version they are using.<br><div><br>So Bird can interoperate with a router that supports 2byte ASN only?<br></div> </div><div><br><div><br>Gerta<br></div></div></div><div id="yahoo_quoted_6029416561" class="yahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Tuesday, August 28, 2018, 2:25:52 PM GMT+2, Ondrej Zajicek <santiago@crfreenet.org> wrote:
</div>
<div><br></div>
<div><br></div>
<div>On Tue, Aug 28, 2018 at 11:48:31AM +0000, gerta toli wrote:<br clear="none">> HI Ondrej,<br clear="none">> <br clear="none">> <br clear="none">> This is my configuration<br clear="none">> <br clear="none">> protocol bgp eBGP4byteASN {<br clear="none">> debug all;<br clear="none">> import all;<br clear="none">> export filter out;<br clear="none">> local as "my-4byteASN";<br clear="none">> neighbor 192.168.0.1 as 65535;<br clear="none">> source address 192.168.0.2;<br clear="none">> }<br clear="none">> <br clear="none">> <br clear="none">> So my peer 192.168.0.1 understands only 2byte ASN , but I have 4byte<br clear="none">> ASN. ASN_Trans is used in case of such scenario by the 4byte ASN routers.<br clear="none">> So supposedly, Bird should send open message using the ASN 23456, since<br clear="none">> it knows that it is peering with an old 2byteASN router. The error im<br clear="none">> showing is below:<br clear="none"><br clear="none">That is how it works: OPEN message itself contains always 2byte ASN or<br clear="none">ASN 23456 in the main ASN field and 4B ASN is stored in optional field,<br clear="none">so it is ignored by the peer that does not understand the optional field.<br clear="none"><br clear="none">If the peer reports Bad peer AS: my_4byteASN, then the peer most likely<br clear="none">understands 4byte ASNs, because it can read the optional field.<br clear="none">Therefore, it should be configured with your 4B ASN as peer ASN.<br clear="none"><br clear="none">The fact that the peer itself uses 2B ASN is irrelevant. The important<br clear="none">distinction is whether the peer understands 4B ASN capability, which<br clear="none">likely is supported by most BGP software/firmware that is not older<br clear="none">than ~10 years.<div class="yqt4912363773" id="yqtfd21711"><br clear="none"><br clear="none">-- <br clear="none">Elen sila lumenn' omentielvo<br clear="none"><br clear="none">Ondrej 'Santiago' Zajicek (email: <a shape="rect" ymailto="mailto:santiago@crfreenet.org" href="mailto:santiago@crfreenet.org">santiago@crfreenet.org</a>)<br clear="none">OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)<br clear="none">"To err is human -- to blame it on a computer is even more so."</div></div>
</div>
</div></div></body></html>