RESILENT LINKS: SW3WHT failure recovery

This is the backbone switch for the observing system in the WHT. Is located at the computers room, communications rack. This device connects the 10 Mbits/s network where the vaxes are, has the fiber interface going to the Liquid Nitrogen plant where the concam and ntpserver1 are connected, and also gives 100 Mbits/s connectivity to the rest of the observing system network and control room.

If this device fails, major problems will occur in the WHT observing system. The connectivity will be lost with the TCS, the NTP servers and other services like Internet access, on line documentation, etc.

Before following the next steps is a good idea to power cycle sw3wht to see if that fixes the problem.

The spare for this device is sw13wht, below it, and the procedure to use it instead of sw3wht is as follows:

1. Switch off sw3wht.

2. Move front UTP cables from sw3wht to sw13wht as described in this table:

   From	To
   sw3wht 1	sw13wht 1
   sw3wht 2	sw13wht 2
   sw3wht 3	sw13wht 3
   sw3wht 4	sw13wht 4
   sw3wht 5	sw13wht 5
   sw3wht 7	sw13wht 7
   sw3wht 8	sw13wht 8
   sw3wht 9	sw13wht 9
   sw3wht 10	sw13wht 10
   sw3wht 11	sw13wht 11
   sw3wht 12	sw13wht 12
   sw3wht 13	sw13wht 13
   sw3wht 14	sw13wht 14
   sw3wht 15	sw13wht 15
   sw3wht 16	sw13wht 16
   sw3wht 17	sw13wht 17
   sw3wht 18	sw13wht 18
   sw3wht 19	sw13wht 19
   sw3wht 20	sw13wht 20
   sw3wht 21	sw13wht 21
   sw3wht 22	sw13wht 22
   sw3wht 23	sw13wht 23

3. Move the fiber in the back of sw3wht to sw13wht

After this is done, it takes a few minutes for the network to come back again.

Any question regarding this document, contact Luis Hernandez