Re: Getting about 10% packet loss with MPLS traffic but not global table traffic

ryanpst88 · ‎12-23-2017

Hi,

Subject covers the issues but here is me pinging from a CE > PE and PE > CE. Thought it was an MTU issue but I still get the same amount of loss (around 10%) in the VRF whether MTU is default or 128 and 0 loss from the non-VRF P2P address range. Any advice?

CE-ROUTER1#ping vrf VRF113 172.31.255.14 r 100
Type escape sequence to abort.
Sending 100, 128-byte ICMP Echos to 172.31.255.14, timeout is 2 seconds:
!!!!!!!.!!!!!!!!.!!!!!!!!!!!!!.!!!!!.!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!
!!!.!!!!!!!!!!.!!!!!!!!!!!!.!!
Success rate is 91 percent (91/100), round-trip min/avg/max = 1/2/4 ms
CE-ROUTER1#ping vrf VRF113 172.31.255.14 r 100 df-bit size 128
Type escape sequence to abort.
Sending 100, 128-byte ICMP Echos to 172.31.255.14, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!..!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!
!.!!!!!!!!!!!.!!!!!!!!!!!.!!!!
Success rate is 90 percent (90/100), round-trip min/avg/max = 1/1/4 ms
CE-ROUTER1#ping 10.255.255.253 r 1000
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 10.255.255.253, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/2/4 ms
CE-ROUTER1#

------------------------------

PE-ROUTER1#ping vrf VRF113 192.168.100.1 r 100 df-bit size 128
Type escape sequence to abort.
Sending 100, 128-byte ICMP Echos to 192.168.100.1, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!.!!!!!!!!!!!!
.!!!!!!!!!!!.!!!!!!!!!!.!!!!!!
Success rate is 92 percent (92/100), round-trip min/avg/max = 1/2/4 ms
PE-ROUTER1#ping 10.255.255.254 r 1000
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 10.255.255.254, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/2/4 ms
PE-ROUTER1#

Both routers are LDP speaker.

CE uplink:

interface GigabitEthernet0/0
 mtu 1524
 ip address 10.255.255.254 255.255.255.252
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip mtu 1500
 ip ospf authentication
 ip ospf authentication-key 123
 ip ospf network point-to-point
 ip ospf dead-interval 5
 ip ospf hello-interval 2
 ip ospf mtu-ignore
 ip ospf cost 5000
 duplex auto
 speed auto
 mpls mtu 1500
 mpls label protocol ldp
 mpls ip
end

PE downlink:

interface GigabitEthernet0/0/0.104
 encapsulation dot1Q 104
 ip address 10.255.255.253 255.255.255.252
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip mtu 1552
 ip ospf authentication
 ip ospf authentication-key 123
 ip ospf network point-to-point
 ip ospf dead-interval 5
 ip ospf hello-interval 2
 ip ospf mtu-ignore
 ip ospf cost 5000
 mpls mtu 1552
 mpls label protocol ldp
 mpls ip
end

NB: Actually using public IPs for the P2P just changed to 10.255.255.x for obvious reasons.

Georg Pauwen · ‎12-23-2017

Hello,

the IP and MPLS MTU sizes of your interfaces are different, is there a specific reason for that ? What if you use the defaults (undo the mtu and mpls mtu commands to enable the defaults, 'no ip mtu', 'no mpls mtu') ?

ryanpst88 · ‎12-23-2017

Hey,

I'd been playing around with MTU, they were originally the same. I've just changed them now though for completeness so it's IP/MPLS mtu 1500 on both sides but still loss. You can see I still got the loss when I was pinging with 'df-bit size 128' so it's not an MTU issue (unless MTU needs to be lower than this which it won't be surely).

Pinging from PE to CE with new MTU:

PE-ROUTER1#ping vrf VRF113 192.168.100.1 r 1000
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 192.168.100.1, timeout is 2 seconds:
!!!!.!!!!!!!.!!!!.!!!!!!!!!!!!.!!!!!!!!.!!!!!!!!!!!!.!!!!!!.!!!!!!!!!!
!!.!!!!!!!!!!!!..!!!!!!!!!!!.!!!.!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!!.
!!!!!!!!!!!.!!!!.!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!
!!!!!!!.!!!!!!!!!!!!.!!.!!!!!!!!!!!!.!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!
!.!!!!!!!!!!.!!!!!.!!!!!!!!!!!.!!!!!!!.!!!!!!!!!!!.!!!!.!!!!!!!.!!!!!!
!.!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!.!!!!!!!!!!!!
.!!!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!.!!!!!.!.!!!!!!!!!!.!
!!!!!!!!!!!.!!!!!!.!!!!!.!!.!!.!!!!!.!!!!.!!!!!!!!.!!!.!!!!..!!!!!!!.!
!!!!!!!!!!.!!!!!!!!!.!!!!!!!!!!.!!.!!!!!!!!!.!!!!!!!!!!!.!!!!!!!!!!!.!
!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!!!!!!.!!!!!!!!!
.!!!!!!!!!!!.!!!!!!!!!!!!.!!!!!.!!!!!!!!!!!!.!!!!!!!!!!!.!!.!!!!!!!!!!
!.!!!!!!!.!!!.!!!!!!!!!!!!.!!!!!!!.!!.!!!!!!!!!!!.!!!!!!!!!.!!!!!!!.!!
!!!!!!!!!!.!!!!!!!!!!!!.
Success rate is 89 percent (773/864), round-trip min/avg/max = 1/2/16 ms

Georg Pauwen · ‎12-23-2017

Hello,

can you post the full configs of both routers, PE and CE ? Also, what routing is configured for the vrf ?

ryanpst88 · ‎12-23-2017

Both configs attached as text files to this message.

Changed a few things for security reasons but they were just variables (AS, public range, VRF names).

Thanks.