03-23-2008 08:31 AM - edited 03-05-2019 09:55 PM
IOS (tm) MSFC2 Software (C6MSFC2-JSV-M), Version 12.1(8b)E9,
sh ip int brief
Interface IP-Address OK? Method Status Protocol
Vlan3 10.163.40.225 YES NVRAM up up
Vlan4 10.163.41.237 YES NVRAM up up
Vlan7 10.180.0.1 YES manual up up
Vlan9 10.180.0.6 YES manual up up
Vlan12 10.180.0.9 YES manual up up
Vlan17 10.180.0.18 YES manual up up
Vlan100 unassigned YES NVRAM administratively down down
Vlan101 192.168.0.174 YES manual up up
Loopback0 10.163.40.14 YES NVRAM up
can anyone tell me how we can check if vlans are in same subnet or different
03-23-2008 08:38 AM
Probably I don't really understand what you are askyng....but try to copy and paste this command in your console
sh int | i Vlan|Internet address
03-23-2008 08:52 AM
Vlan3 is up, line protocol is up
Internet address is 10.163.40.225/28
Vlan4 is up, line protocol is up
Internet address is 10.163.41.237/30
Vlan7 is up, line protocol is up
Internet address is 10.180.0.1/30
Vlan9 is up, line protocol is up
Internet address is 10.180.0.6/30
Vlan12 is up, line protocol is up
Internet address is 10.180.0.9/29
Vlan17 is up, line protocol is up
Internet address is 10.180.0.18/30
Vlan100 is administratively down, line protocol is down
Vlan101 is up, line protocol is up
Internet address is 192.168.0.174/29
Internet address is 10.163.40.14/32
03-23-2008 08:45 AM
Hi Mahesh,
Issue the 'show ip route connected" command.
This will show you the subnets with masks for the vlan interfaces, and you can check which vlan interface belongs to which subnet.
Cheers:
Istvan
03-23-2008 08:56 AM
sh ip route connected
C 127.0.0.0/8 is directly connected, EOBC0/0
10.0.0.0/8 is variably subnetted, 748 subnets, 16 masks
C 10.163.40.224/28 is directly connected, Vlan3
C 10.163.41.236/30 is directly connected, Vlan4
C 10.163.40.14/32 is directly connected, Loopback0
C 10.180.0.16/30 is directly connected, Vlan17
C 10.180.0.8/29 is directly connected, Vlan12
C 10.180.0.4/30 is directly connected, Vlan9
C 10.180.0.0/30 is directly connected, Vlan7
192.168.0.0/29 is subnetted, 1 subnets
C 192.168.0.168 is directly connected, Vlan101
can u explain we what this mean
03-23-2008 10:38 AM
Hi Mahesh,
For example:
Interface vlan3 is in the 10.163.40.224 subnet with a 28 bit long subnet mask.
The same way you can check the subnet for other vlan interfaces.
The good thing with the "show ip route connected" command is that you don't have to calculate the subnet from the ip address and mask of the vlan interface.
This shows you the subnets and masks directly.
Cheers:
Istvan
03-23-2008 08:46 AM
Just do a show runn and look at the layer 3 SVI's and see how they are masked adn that will tell you if they are in the same address range, they should not be . My guess by looking them is that they are connecting links with a /30 mask.
03-23-2008 08:54 AM
hi thanks for ur reply
can u explain me in deep what u mean?
03-23-2008 09:00 AM
I think you need a little bit of theory on subnetting:
IP Addressing and Subnetting for New Users
03-23-2008 09:20 AM
thanks for ur reply
i need understanding on subnets
that link will help
03-23-2008 09:00 AM
The switch won't allow you to enter overlapping subnets on different SVIs, therefore all the IP addresses you've listed are on different subnets.
Example,
interface Vlan840
ip address 1.1.1.1 255.255.255.128
shutdown
!
interface Vlan841
ip address 1.1.1.3 255.255.255.128
shutdown
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#int vlan 840
Router(config-if)#no shut
Router(config-if)#int vlan 841
Router(config-if)#no shut
1.1.1.0 overlaps with Vlan840
Vlan841: incorrect IP address assignment
Router(config-if)#
HTH,
__
Edison.
03-23-2008 09:16 AM
thanks for ur reply
so vlan7,4 17 have subnet/30
so are these vlans in same subnet then
03-23-2008 06:49 PM
Your vlans are not on the same subnet. Your router will not allow you to have overlapping subnets.
Mark
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