Hi ,
I have posted a couple of times in the past and always get the best answers or good advices to get my problem resolved, thank you very much community!
We ordered a pair of QFX-5120 for our Colo solution last Nov, but expect the delivery around end of this October. In order to have the configuration ready and tested, I got a pair of QFX-5100 without Juniper support.
After have the Virtual Chassis configured, it works perfectly for the "master", but after we force it to switch master the connection failed.
Everything looks fine, but the problem persisted - wonder if someone run into this problem and resolved or can shed some light on the cause of the problem.

root@SJ-Colo-Core-5100-02> show virtual-chassis
Preprovisioned Virtual Chassis
Virtual Chassis ID: 5fcb.f2af.8442
Virtual Chassis Mode: Enabled
Mstr Mixed Route Neighbor List
Member ID Status Serial No Model prio Role Mode Mode ID Interface
0 (FPC 0) Prsnt VF3716340205 qfx5100-48s-6q 129 Master* N VC 1 vcp-255/0/52
1 vcp-255/0/53
1 (FPC 1) Prsnt VF3716350646 qfx5100-48s-6q 129 Backup N VC 0 vcp-255/0/52
0 vcp-255/0/53
{master:0}
root@SJ-Colo-Core-5100-02> show virtual-chassis vc-port
fpc0:
--------------------------------------------------------------------------
Interface Type Trunk Status Speed Neighbor
or ID (mbps) ID Interface
PIC / Port
0/52 Configured 5 Up 40000 1 vcp-255/0/52
0/53 Configured 5 Up 40000 1 vcp-255/0/53
fpc1:
--------------------------------------------------------------------------
Interface Type Trunk Status Speed Neighbor
or ID (mbps) ID Interface
PIC / Port
0/52 Configured 5 Up 40000 0 vcp-255/0/52
0/53 Configured 5 Up 40000 0 vcp-255/0/53
root@SJ-Colo-Core-5100-02> ping 10.33.67.21
PING 10.33.67.21 (10.33.67.21): 56 data bytes
64 bytes from 10.33.67.21: icmp_seq=0 ttl=64 time=10.849 ms
64 bytes from 10.33.67.21: icmp_seq=1 ttl=64 time=11.151 ms
^C
--- 10.33.67.21 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 10.849/11.000/11.151/0.151 ms
{master:0}
root@SJ-Colo-Core-5100-02> ping 10.33.67.22
PING 10.33.67.22 (10.33.67.22): 56 data bytes
64 bytes from 10.33.67.22: icmp_seq=0 ttl=64 time=21.698 ms
64 bytes from 10.33.67.22: icmp_seq=1 ttl=64 time=33.130 ms
^C
--- 10.33.67.22 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 21.698/27.414/33.130/5.716 ms
root@SJ-Colo-Core-5100-02> request chassis routing-engine master switch
Toggle mastership between routing engines ? [yes,no] (no) yes
root@SJ-Colo-Core-5100-02> show virtual-chassis
Preprovisioned Virtual Chassis
Virtual Chassis ID: 5fcb.f2af.8442
Virtual Chassis Mode: Enabled
Mstr Mixed Route Neighbor List
Member ID Status Serial No Model prio Role Mode Mode ID Interface
0 (FPC 0) Prsnt VF3716340205 qfx5100-48s-6q 129 Backup* N VC 1 vcp-255/0/52
1 vcp-255/0/53
1 (FPC 1) Prsnt VF3716350646 qfx5100-48s-6q 129 Master N VC 0 vcp-255/0/52
0 vcp-255/0/53
root@SJ-Colo-Core-5100-02> ping 10.33.67.21
PING 10.33.67.21 (10.33.67.21): 56 data bytes
ping: sendto: Network is down
ping: sendto: Network is down
ping: sendto: Network is down
^C
--- 10.33.67.21 ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss
{backup:0}
root@SJ-Colo-Core-5100-02> ping 10.33.67.22
PING 10.33.67.22 (10.33.67.22): 56 data bytes
ping: sendto: Network is down
ping: sendto: Network is down
^C
--- 10.33.67.22 ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss
Thanks in Advance!
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KEITH
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