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Does anyone know whether it is possible to remotely change the mgmt IP, vlan and default gw of a HP Switch without losing connectivity when connecting via ssh to said IP?

  • Create new (mgmt) vlan
  • Create svi in new vlan
  • Change default gw to network of new vlan IP

Thanks

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  • Would it be possible to reconnect to the other IP? Create new vlan - have connectivity; SVI in vlan - have connectivity; define vlan as mgmt vlan - do I loose connectivity here?; change default gw - can I reconnect in the new network? – Max Dec 19 '14 at 10:25
  • Depends on the device. Some devices only support one SVI or access to only one management IP while others allow multiple SVIs/IPs and allow management access to all/some of them. We would really need to know the model of the device to make this determination. – YLearn Dec 19 '14 at 22:09
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer. – Ron Maupin Jan 5 at 18:07
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This depends entirely on the switch model.

Simple layer-2 switches, "not likely". The issue is the inability to enter an atomic set of commands. Each configuration change will be active the instant it's entered. So, when you enter primary-vlan xx, the minute you hit enter your connection will fail.

With layer-3 switches, "Yes". But it takes a careful sequence. Be sure your moving of the mgmt interface and any associated route(s) will not break traffic forwarding/routing through the switch. Bring up IP on a different SVI (vlan). Then access the switch through that new interface, preferably from a local host (i.e. host in the same subnet) to avoid any routing issues. Then move the management vlan, if that model has any notion of "management vlan".

[Doing an in-place network / management redesign with a few nortel (avaya) switches was a real test. That ultimately took a bit of netmask juggling, proxy-arp, /32 routing *grin* (yes, a host can live on the wrong network), and leap-frog telnet's... and that was on a switch down the hall from me.]

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  • I understand, thanks for the clarification. I am doing the changes on 2620 and 2920. If I create a new SVI and all SSH traffic to it I don't think I'll be able to access it. I canonly set 1 default GW and the new IP will be in a different network. If I had access to a local host on that network I could do it. Perhaps I can SSH into the switch from it's new default GW (breakout router). Alternatively, would it be possible to have the switch pull a new config file from a TFTP server on boot? – Max Dec 23 '14 at 9:56

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