2 IP on a NIC

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Jun 12th, 2008
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I have a server wit 2 IPs [primary & Secondary]assigned to a NIC.Both these IPs belong to different VLANs. This server is connected to an L3 switch of 6500 series. How do I make this work? What do I configure at the switchport end? The switch is connected to a WAN router.

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n.nandrekar Thu, 06/12/2008 - 00:42
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Can you elaborate on what your aim is?

You can configure the port on 6500 to be a switchport trunk, allowing the vlans you have configured on the server. Then you can create SVI (interface vlan) for those vlans and give ip addresses on them reflecting the subnets you have configured on the server.



deepa.muralidharan Thu, 06/12/2008 - 00:52
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I have a system assigned to VLAN 10 belonging to 192.x.x.x. This IP is not visible on the WAN. I want to be able to telnet to this system from the othere end of the WAN. So, We decided to give an IP of range 172.x.x.x as this is visible on the WAN. We can't change the IP 192.x.x.x as we have some of our websites hosted here. I need access only to telnet to this server to work. How do I do this?

I can assign a trunk to the port connecting the server, but at the server end, the system do not understand trunking.

How do I go about this ?

n.nandrekar Thu, 06/12/2008 - 01:30
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You said that both the IPs that you gave to the server belong to different vlans. SO I thought that you have configured different vlans on the NIC and that it understands trunking.

To solve your query, on which interface is your default gateway address configured? If you have configured the ip in 192.x.x.x range on a vlan interface on the 6500, configure the 172.x.x.x in the same interface ... but just as secondary.

you can do this but mentioning "secondary" after ip addr command :

"ip addr x.x.x.x 255.255.x.x secondary"

If this doesnot answer your question, can you give details on the config of the interface connected to the server? and also the connectivity details of how 192.x.x.x is accessed from outside and 172 over the wan link.




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