Switching Ethernet CAT5 RJ45 cables remotely

[Ron Kinner]

This will probably get moved to some other newsgroup but here goes. Reference my earlier post: http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x257c50011d20d6118ff40090279cd0f9,00.html

for more details.

We are looking for a CHEAP FOOLPROOF way to automatically bring our backup server onto a network when the primary fails. We looked at each having the same IP address and unplumbing one and plumbing the other but this takes a bit more access than we want to give our shift operators.

I suggested using a telnet manageable switch and turning off one port and turning on the other when they need to switch. This is better since the shift guys don't need the root password but still not foolproof since they could forget to turn off the first port which would screw everything up if the primary were not completely dead. I have proposed a script which would do the telnet logon and disable/enable port thing and we may go with that.

It occurred to me that there may be a device out there already - sort of a remote control cat5 cable A-B switch. Anybody seen one? BlackBox offers one but it it's more an A-Z switch and costs a lot more than we want to spend. They have another which requires a modem but we would prefer a network connection.

Ron

[Christopher Caldwell]

Use ServiceGuard and the IP/LAN switching will be handled for you without operator intervention.

A solution with operator intervention:
If you have access to the ethernet switch (i.e. it's manageable)
-configure both boxen
-configure telnet on the switch
-plug both into the switch
-down the port on the backup box (i.e. just turn it off at the switch
in Cisco'ease that would be
conf t
int f0/portnum[1-24]
shut

when you want to switch hosts
conf t
int f0/portnum[running host]
shut
int f0/portnum[backup host]
no shut

[harry d brown jr]

Well the real cheap way is to not worry about it too much, especially if cost is a concern. We have over 400 Hp 9000 servers and I think we lose one network card about every two years (and it takes Hp less than 4 hours to replace it). This must not be a very critical server, correct? If it is, how much would be lost per hour if the server was unreachable? Then you take the outage loss and determine if you should purchase mc/sg.

live free or die
harry

[Ron Kinner]

They know about Service Guard but are still recovering from the trauma (and downtime) of upgrading from 10.20 to 11.0 so have flatly refused to consider the idea. They just want something simple with only minor changes to the system.

If we go with the switch and script idea which I have proposed the switch will be a 3Com since we have a bunch of them surplus.

Ron