08-05-2016 03:15 PM
Hi community,
I need your help to the next case, I try to establish a Pseudowire between an ASR902 and ASR9000.
In the ASR we configure the MTU in bridge-domian to 9216, but in ASR902 the maximum MTU in the VFI is 9180. The Pseudowire is DOWN for the MTU mistmatch
I know that we can change the MTU in ASR9000 to 9180 to the Pseudowire work, but my question is in reference about the maximum MTU supported in ASR902, this because in the ASR9000 we have a lot pseudowires into the this bridge-domain to others ASR9k and ME3600x, ME3800x.
Configuration in ASR9002, the MTU is set to 9180
ASR902_PE_SITE_B#show mpls l2transport vc 2829 detail | inc erro|MTU
Last error: Pseudowire MTU mismatch with peer
MTU: local 9180, remote 9216
transit packet drops: receive 0, seq error 0, send 0
ASR902_PE_SITE_B#
ASR902_PE_SITE_B(config)#l2vpn vfi context TEST_L2VPN
ASR902_PE_SITE_B(config-vfi)#mt
ASR902_PE_SITE_B(config-vfi)#mtu ?
<1500-9180> Maximum Transmission Unit value
<cr>
Configuration in ASR9000, the MTU is set to 9216
RP/0/RSP0/CPU0:PE-ME-SITE_A#
bridge group TEST_L2VPN
bridge-domain CULIA_MAZA
mtu 9216
interface GigabitEthernet0/1/0/0.2829
!
vfi CULIA_MAZA
vpn-id 28290
!
neighbor 192.168.74.X pw-id 2829
RP/0/RSP0/CPU0:PE-ME-SITE_A#show l2vpn bridge-domain neighbor 192.168.74.83 pw-id 2829 detail | inc "MTU|Err|type"
Fri Aug 5 17:04:32.385 CDT
Bridge MTU: 9216
PW type Ethernet, control word disabled, interworking none
MTU 9216 9180
PW type Ethernet Ethernet
VCCV CV type 0x2 0x2
VCCV CC type 0x6 0x2
Error: MTU mismatched
RP/0/RSP0/CPU0:PE-ME-SITE_A#
I really apreciate your help.
Regards.
Solved! Go to Solution.
08-17-2016 09:21 AM
the mtu for the PW is merely a signaling thing and doesnt affect any fragmentation or forwarding.
the mtu can also be taken from the attachment circuit.
the maximum mtu for the asr902 is also 9216.
cheers!
xander
08-18-2016 05:16 AM
for the asr9000 it is a bit more straight forward, in the l2vpn configuration youhave direct control in the pw class what type of transport you want to use.
for the asr900 the config mode(l) defines a vc type 4 or 5.
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l2_vpns/configuration/xe-3s/mp-l2-vpns-xe-3s-book/mp-any-transport-xe.html#GUID-FB013E0C-B37F-48CF-B2B0-374A45B9B9EC
it generally doesnt really matter what way you go about, 4 or 5. Unless you have very strict qos (propagation) requirements and separation between exp and dot1p. If you dont care about that, either one is fine.
cheers!
xander
08-17-2016 09:21 AM
the mtu for the PW is merely a signaling thing and doesnt affect any fragmentation or forwarding.
the mtu can also be taken from the attachment circuit.
the maximum mtu for the asr902 is also 9216.
cheers!
xander
08-17-2016 04:38 PM
Hi Xander,
Thanks for your support, I changed VFI to Xconnect and now the MTU is taken for the physical interface to 9216.
l2vpn xconnect context CLIENT
member GigabitEthernet0/1/1 service-instance 1234
member 1.1.1.1 1234 encapsulation mpls
I see the diference in the new format to configure L2VPN in ASR900 where we don't configure a SVI whit xconnect. In this case the MTU is taken for the SVI.
Is it possible configure a pseudowire in "Vlan-Mode" in ASR900?
PW VC Type 5 port mode
PW VC type 4 VLAN mode
Regards.
08-18-2016 05:16 AM
for the asr9000 it is a bit more straight forward, in the l2vpn configuration youhave direct control in the pw class what type of transport you want to use.
for the asr900 the config mode(l) defines a vc type 4 or 5.
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l2_vpns/configuration/xe-3s/mp-l2-vpns-xe-3s-book/mp-any-transport-xe.html#GUID-FB013E0C-B37F-48CF-B2B0-374A45B9B9EC
it generally doesnt really matter what way you go about, 4 or 5. Unless you have very strict qos (propagation) requirements and separation between exp and dot1p. If you dont care about that, either one is fine.
cheers!
xander
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide