Data Center (VDX)

 Requesting help :VDX 8770 unable to ping a directly connected MLX router

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thaizoun's profile image
thaizoun posted 09-01-2021 18:56

Hello All,

I am new to the VDX platform. We have a VDX fabric in our lab .We have two VDXs directly connected to  two MLXes.We configured OSPF on both the MLXes and the VDXs. The ports are routed ports with OSPF set on them .OSPF neighborships gets established and we see ospf  routes on the MLXes and we can ping VDXs from the MLXs  but not from the VDXs even though we see the ip of the MLXs in the arp table within the VDX.

we configured rb 4 from within the principal rb (rb1)


I am not sure why we cannot ping the MLX from within rb1 .We can ping the MLX from the rb4 itself , but not from within the principal rb ( fabric )


rb1# sh lldp nei rbridge-id 4
Local Intf    Dead Interval  Remaining Life  Remote Intf                       Chassis ID        Tx           Rx                  System Name
Te 4/2/14     120            115             0024.388f.803d                    0024.388f.8000    10           6                   MLXe4-3

Total no. of Records: 1
rb1# conf t
Entering configuration mode terminal
rb1(config)# rbridge-id 4
rb1(config-rbridge-id-4)# do show ip ospf nei rbridge-id 4
Number of Neighbors is 1, in FULL state 1

Port           Address         Pri State      Neigh Address   Neigh ID        Ev      Opt Cnt
Te 4/2/14        1   FULL/OTHER         5       2   0
rb1(config-rbridge-id-4)# do show arp  rbridge-id 4
Entries in VRF default-vrf : 1
Address          Mac-address     L3 Interface  L2 Interface  Age         Type
--------------------------------------------------------------------------------         0024.388f.803d  Te 4/2/14     Te 4/2/14     00:01:35    Dynamic
rb1(config-rbridge-id-4)# do ping
Type Control-c to abort
PING ( 56 data bytes
ping: sendto: Network is unreachable
ping: sendto: Network is unreachable
ping: sendto: Network is unreachable
^C^C--- ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss



MLXe4-3#sh lldp nei
Total number of LLDP neighbors on all ports: 1
Lcl Port Chassis ID      Port ID         Port Description        System Name
2/14     0027.f810.c59c  TenGigabitEthe~                         rb4
MLXe4-3#sh ip ospf nei
Number of Neighbors is 1, in FULL state 1

Port   Address         Pri State      Neigh Address   Neigh ID        Ev        Opt Cnt
2/14        1   FULL/OTHER         5         2   0
Sending 1, 16-byte ICMP Echo to, timeout 5000 msec, TTL 64
Type Control-c to abort
Reply from        : bytes=16 time=1ms TTL=64
Success rate is 100 percent (1/1), round-trip min/avg/max=1/1/1 ms.



Any help /tips would be highly appreciated.





Deep Bakul Bhojani's profile image
Deep Bakul Bhojani

Hello Talal,

On the vdx fabric the Layer2 works together however for the layer3 each VDX will need to have route and path to the MLX. So for this particular case you should be able to ping from the actual rb 4 VDX (ssh into the rb 4) to the MLX IP.




thaizoun's profile image

Hi Deep,

Thank you for responding to my question and for the explanation.I thought so too as i am able to ping the MLXes from rb4 & rb5