Drops between 2PE connected directly

[faradajay]

Hi experts,

Need help .

CustomerMGW-----SW-(trunk)--------(2 Sub-interface)-PE1-----------------PE2

MGW is telecom device.

PE1 and PE2 is directly connected with gig port.MGW is customer.

Form MGW device to connection is terminating on SW and they assigned ip from different subnet.

On PE1, port connected to SW , 2 subinterface is made and  2 vrf is formed say vrf voice and signal.

One subinterface is in  vrf voice and other is in signal.

Here MP-BGP ,ldp ,MPLS L3VPN and ospf is used

Both PE are in same AS and form ibgp neibhorship with loopback.

In peak hrs (when traffic is high),there is drop observed when pinging from PE2 to Customer End device( MGW ) IP.

Observation  when traffic is high (500Mb):

From PE2 to PE1

1>ping P2P ip without any drops.

2>Ping to Loopback from each-other ,no drop observed.

3>Ping to PE2 subinterfaces belonging to VRF ,observed drops.(ping vrf cmd)

4>Ping to PE2 to end device (MGW) ip ,observed drops.(ping vrf cmd)

from PE1 .

1>ping P2P between PEs ip ,without any drops.

2>Ping to Loopback from each-other ,no drop observed.

3>Ping to End device (MGW),no  drops observed.(ping vrf cmd)

4>ping to loopback ip using ping mpls PE2_loopback_ip, observed drops.(this is happening in normal hrs also)

just normal configuration is used.no policy is applied any of the PE.

what would be reason of these drops????/

Please help

BR//

Ajay

[Mahesh Gohil]

Hello,

It seems you are facing similar issue what we have faced 3-4 times. So far we still not have root cause of this issue but we solved it by recreating sub-interface again. You may try it in maintenance window.

Also there is small confusion:

From PE2 to PE1

3>Ping to PE2 subinterfaces belonging to VRF ,observed drops.(ping vrf cmd)    >>> does it mean self-ip is also showing drops?

from PE1

4>ping to loopback ip using ping mpls PE2_loopback_ip, observed drops.(this is happening in normal hrs also)  >>> this looks bit strange. Can you confirm it again.

Regards # mahesh

[faradajay]

Hi mahesh,

thanks for your reply.

Sorry for mistake.

From PE2 to PE1

Ping to PE1 subinterfaces belonging to VRF ,observed drops.(ping vrf cmd)

and

from PE1

4>ping to loopback ip using ping mpls PE2_loopback_ip, observed drops.

yes i am getting drop while pinging loopback of PE2 using ping mpls PE2_loopback_ip cmd.

thanks and Regards,

AJAY YADAV

[Mahesh Gohil]

Hello Ajay,

Thanks for clarification.

Have you tried recreating sub-interface at PE2?

If not please try it during low traffic period.

Regards # Mahesh

[faradajay]

Hi Mahiesh,

Could MTU Mismatch be the issue of dropping?

On My side(PE1) MPLS MTU is 1500 B and Other side (PE2) ,MPLS MTU is 1488 B.

On PE1 ,IP MTU is 1500,so what will be the recommended MPLS MTU?

( we are using  MPLS L3VPN .)

please suggest.

Thanks and regards,

Ajay

[faradajay]

Hi.

Mahiesh,

the dropping issue is resolved by making MTU size=1500 on both side.

In normal ping , there is nodrops observe ie ping vrf name  x.x.x.x

But still

i am getting drop while pinging loopback of PE2 using ping mpls PE2_loopback_ip cmd.

Herer --

PE2---->P1-AHMD-M120-RE0)  And PE1--->AHM-6804..

AHM-6804#ping mpls ipv4 10.38.150.1 32 repeat 100

sending 100,120-byte MPLS echo(es) to 10.38.150.1,timeout is 2 second(s).

Codes: '!' - success,   'Q' - request not transmitted,

       '.' - timeout,   'U' - unreachable,

       'R' - downstream router but not target

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!

Success rate is 98 percent(98/100),round-trip min/avg/max= 1/2/5 ms.

but from PE2(P1-AHMD-M120-RE0) to PE1(AHM-6804)...

ravish@P1-AHMD-M120-RE0

>  ping mpls ldp count 100 size 1500 10.38.150.37

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

---  lsping statistics ---

100  packets transmitted, 100 packets received

, 0%  packet loss

ravish@P2-AHMD-M120-RE0>

ping mpls ldp count 100 size 1500 10.38.150.37

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

---  lsping statistics ---

100  packets transmitted, 100 packets received,

0%  packet loss

please help experts on this....