[j-nsp] Making juniper handle native vlans

[Alexander Arsenyev (GU/ETL)]

hello,

Word "MTU" comes to mind... Try to pre-fragment packets BEFORE they hit the switch
or use RSVP with MTU signalling
http://www.juniper.net/techpubs/software/junos/junos63/swconfig63-mpls-apps/html/rsvp-overview11.html
Disclaimer - I don't use it myself so it might just work!

If majority of Your traffic across this switch is TCP then another not-so-obvious option 
is to lower TCP MSS value - on Solaris 5.8 it could be done with 2 settings:
ip_path_mtu_discovery=0
tcp_mss_def_ipv4=1448 or lower (1460-3x4=1448, to accomodate two MPLS labels and one .1q tag)  
HTH,
Cheers
Alex

-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net]
Sent: 18 February 2005 22:46
To: juniper-nsp at puck.nether.net
Subject: [j-nsp] Making juniper handle native vlans


I think this has been here asked before, but is there ANY way to trick a 
jnpr into handling mixed .1q tagged and untagged frames on the same 
interface a la native vlans?

I ask not because I think that native vlans are in any way the "right 
thing", but because I need to work around a certain ASIC limitation on 
some certain Crisco switches which can only handle an ethernet frame + 4 
extra bytes. This is enough room for a .1q tag, or for a single MPLS tag, 
but not both. Thus the only way to pass MPLS tags through said switch 
while still doing .1q vlans on the interfaces is to run the MPLS speaking 
portion via a native vlan. This would work fine, except that the other 
side is Juniper, which doesn't get along with this.

Someone want to hack up an fpga image that I can slap onto a GE PIC? :)

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
http://puck.nether.net/mailman/listinfo/juniper-nsp