[c-nsp] reacheability issue in MEL link

[Ahmed Mohamed]

<CE>--------------------------------Metroethernet(carrier)---------------------<switch>----ethernet(cable)-----<PE>

for a link as simple as above, if :
+ the CE , the Agg. switch and the PE interfaces are in the same vlan
+ the CE and the PE IP interfaces are in the same subnet

the i must (at least) have an entry in arp table, and ping successful, which
is not the case

what was getting me crazy , is that all interfaces are up-up all the time,
but i just recieved a feedback today that MetroEthernet carriers have NTU's
acting as Ethernet HUB, so as long as they are functional , you will have
the interfaces up-up even if the circuit is broken inside the carrier !!!

tomorrow i will order dual dispatch to both ends, will test circuit
termination at both ends

"traceroute mac" feature is not in CE or PE IOS



On Wed, Feb 4, 2009 at 1:25 PM, Ahmed Maged (amaged) <amaged at cisco.com>wrote:

> Troubleshoot layer by layer.
>
> If the lower layers doesn't work, don't expect anything to behave
> properly.
>
> Follow the L2 frame with (ltrace) if available on your IOS.
>
> How about debugging?
>
> Can you install a sniffer?
>
> What do you see on the interfaces counters?
>
> Did you try anything else other than ping, maybe ICMP is blocked.
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Ahmed Mohamed
> Sent: Tuesday, February 03, 2009 2:28 AM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] reacheability issue in MEL link
>
> Hello,
>
> this is a real life problem still occuring, and have no idea what may be
> causing it ..
>
> we are providing an internet direct service to our customer vial MEL
> (Metro
> Ethernet Link)
>
> CE (CS-7206 VXR) fe2/0.36 ------------------Etherlink(local
> carrier)---------------- WS-3759G-24TS--PE(CS-7000)
>
> the solution is providied using a carrier to link the customer CE to an
> aggregated switch, using Metro Ethernet
> configuring vlan 36 and using dot1q encapsulation
> then from the aggregating switch to the PE router using also
> encapsulation
> dot1q for vlan36
>
> all interfaces are up-up , and still ping fails !!
>
> i tried everything, resetting ports, switches, reconfigure interfaces
> ..etc.
> still no joy
>
> any idea what could be causing the problem ?
>
> ========================================================================
> CE:
> -----
> interface FastEthernet2/0.36
>  bandwidth 61440
>  encapsulation dot1Q 36
>  ip address 57.78.2.6 255.255.255.252
> ========================================================================
> Agg. switch:
> ------------------
> interface GigabitEthernet1/0/9
>  switchport trunk encapsulation dot1q
>  switchport trunk native vlan 3109
>  switchport trunk allowed vlan 36,3109
>  switchport mode trunk
>  switchport nonegotiate
>  duplex full
>  speed 100
>  mls qos trust cos
>  spanning-tree bpdufilter enable
> ========================================================================
> PE:
> ------
>  interface FastEthernet5/1/1.36
>  bandwidth 61440
>  encapsulation dot1Q 36
>  ip address 57.78.2.5 255.255.255.252
>  no ip redirects
>  no ip proxy-arp
>  no ip route-cache
>  no cdp enable
> ========================================================================
> bmil305#sh int FastEthernet5/1/1.36
> FastEthernet5/1/1.36 is up, line protocol is up <<<<<<
> Hardware is cyBus FastEthernet Interface, address is 0003.fe91.b8a9 (bia
> 0003.fe91.b8a9)
>  Internet address is 57.78.2.5/30
>  MTU 1500 bytes, BW 61440 Kbit, DLY 100 usec,
>     reliability 255/255, txload 1/255, rxload 1/255
>  Encapsulation 802.1Q Virtual LAN, Vlan ID  36.
>  ARP type: ARPA, ARP Timeout 04:00:00
> ========================================================================
> pmil2534#sh int Fa2/0.36
> FastEthernet2/0.36 is up, line protocol is up  <<<<<<
>  Hardware is i82543 (Livengood), address is 0022.be8b.1038 (bia
> 0022.be8b.1038)
>  Description: --- To bmil305 - FE5/1/1.5
>  Internet address is 57.78.2.6/30
>  MTU 1500 bytes, BW 61440 Kbit, DLY 100 usec,
>     reliability 255/255, txload 1/255, rxload 1/255
>  Encapsulation 802.1Q Virtual LAN, Vlan ID  36.
> ========================================================================
> ping pe to CE fails:
> ----------------------------
> bmil305#ping 57.78.2.6   <<<<<<,
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 57.78.2.6, timeout is 2 seconds:
> .....
> Success rate is 0 percent (0/5)
> ========================================================================
> PE to internet (google) successfully:
> ------------------------------------------------------
> bmil305#ping 216.239.59.147 source fast 5/1/1.36 repeat 100 size 500
> Type escape sequence to abort.
> Sending 100, 500-byte ICMP Echos to 216.239.59.147, timeout is 2
> seconds:
> Packet sent with a source address of 57.78.2.5
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> Success rate is 100 percent (100/100), round-trip min/avg/max =
> 36/40/112 ms
> ========================================================================
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