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Your physical switches should have an MTU larger then 1600 I believe. You can try 1650.
Please check out the documentation, it is stated there pretty clearly.
Rule is simple- Wherever you have overlay Networks between Source-Destination- MTU should be changed . For Eg : Edge Transit is connected to SW1 and Tier0-Tier1 communication is happening via SW2 - MTU change is required only at SW2 .
after some MTU checks on the infrastructure, the issue has been solved for 50% i guess.
however, a weird situation occurring in my lab is:
Most of the transport nodes' VTEP(Node A, B, C) which are under same subnet(vlan 172.16.1.0/24), including the edge VM, have no problems on dealing with N-S traffic. the VMs residing on this node which logical switch(LS-1) also covers, can browse the internet without any issues.
Only the transport node's VTEP(Node D) which is under different subnet(vlan 172.24.1.0/24) have problems on dealing with N-S traffic. the VMs residing on node D which logical switch(LS-1) also covers, cannot browse the internet, they could only ping and resolve hostname in the terminal, but these VMs don't have any problems on E-W traffic(such as web and smb).
P.S. 1. the nsx-t manager didn't show any abnormalities and all the status(such as tunnel or bond) are up.
2. the vlan which VTEP uses can route to each other because the gateway is configured.
3. the hierarchical mode is selected for the logical switch.
4. all the necessary MTUs were set to 1600 for all the possible datapath.
does anyone know why? i hope this is not MTU problem.
Physical Global MTU by default is 1600 ( Min 1280 Max:9000)
Logical Global MTU by default is 1600 (Min 64 Max: 9000)