10-18-2008 11:05 AM - edited 03-06-2019 02:00 AM
I have a cisco 4908 switch with 2 fiber gbics and 1 copper gbic. Actually I just added the copper gbic, because I want to connect an HP procurve 2810 48 port copper rj-45 Gigabit switch. The figer gbics were configured by a cisco guy and they have been working fine for years. I have never configured a layer3 cisco switch but have configured many catalyst 2950 switches. Through that experience I was able to get a link light on the port where I connected the HP procurve (its port 6 and the port was initially shutdown, but I enabled the port and the link light turned on). However I cant get through to my network from the HP Procurve.
I ran "show run" and tried to duplicate the configuration of one of the other fiber ports (port 7) to the newly installed copper gbic port (See the attached graphic). I added a sub interface port (6.1) and made the changes as they were set on port 7.1. However I still cant get through.
The ip address of the 4908 is 10.34.4.91.
The ip address I put on the HP procurve is 10.34.4.77. I added this ip address to port 6.1 becuase the ip address that is on port 7.1 is the ip address of the cisco 2950 that is connected to fiber gbic port 7. I figured that should be the same on port 6 and 6.1. Nevertheless, it didnt work.
Can anyone help me figure out what I'm missing. Thanks!!
10-18-2008 12:26 PM
Hello Danny,
you don't need to set ip addresses on each link
a multilayer switch can use L2 links to connect to other devices:
probably you need only one IP address under a logical interface that is named BVI1
Here the syntax is IRB like (integrated routing and bridging)
Check if the following is present:
int BVI1
ip address 10.34.4.91 255.255.255.0
no shut
the subifs 6.1 and 7.1 must be configured with
int g6/1.1
no ip addr
bridge-group 1
int g7/1.1
no ip addr
bridge-group 1
These must be on global configuration mode check if they are present:
bridge 1 bridge ip
bridge 1 route ip
bridge 1 protocol ieee
This should be a correct config.
Another option if IOS supports it is to use logical interface for Vlan
see
Hope to help
Giuseppe
10-18-2008 12:38 PM
Thanks for the info and the quick response. You mentioned BVi1. Can you explain the significance of int BVi1 and how I can check if it is present.
Also you mentioned global configurations
bridge 1 bridge ip
bridge 1 route ip
bridge 1 protocol ieee
How can I check if these are present?
Thanks Again.
10-18-2008 12:47 PM
Hello Danny,
to get this info you need to use
term len 0
show run
collect the output in a log file try to use a more powerful client telnet like putty for doing this: if you look in other threads the files are text files not screenshots !
in a telnet session to C4908 you need to be in enable mode.
hostname#
BVI1 is the logical L3 interface associated with bridge-group 1.
link for download of putty:
http://www.chiark.greenend.org.uk/~sgtatham/putty/
Hope to help
Giuseppe
10-19-2008 09:44 AM
10-19-2008 12:43 PM
Hello Danny,
I see there is
bridge 1 protocol ieee
I see something I think shouldn't work:
int g7.1
ip address 10.34.4.101 255.255.255.0
int gi8.1
ip address 10.34.4.91 255.255.255.0
In my experience these commands shouldn't even be accepted because these are overlapping ip addresses on Vlan subifs.
I've found an explanation for this:
one of the first lines is:
no ip routing
I would try to implement IRB in the correct way:
if you are not one of two ip addresses to telnet to c4908 do:
get a console access to C4908 and do the following:
conf t
int gi7.1
no ip address
int gi8.1
no ip address
exit
ip routing
bridge 1 bridge ip
bridge 1 route ip
int bvi1
ip address 10.34.4.91 255.255.255.0
no shut
the key parameter is no ip routing with this command the switch behaves like a L2 switch.
By using ip routing the behaviour becomes L3 switch.
Hope to help
Giuseppe
10-19-2008 01:15 PM
Thanks for the info, however on port 7 and port 8 I have a cisco 2950 switch. All those switches are working fine.
The problem I'm having is getting the HP Procurve (which is connected to port 6) to communicate with the rest of my network.
Are you saying that by making the changes you suggested, the HP Procurve will be able to communicate to the rest of my network? Also will my existing switches on port 7 and 8 continue to work properly?
Thanks Again.
10-20-2008 01:07 AM
Hello Danny,
I was suggesting what according to my experience is a working configuration.
However, I understand your point of view.
Let's not consider the problem of the general config.
You need to check the behaviour of the link between the two devices.
on C4908 with current config:
ethernet frames with vlan-id 1 are sent out with no Vlan tag: (native keyword)
you need to check on the HP procurve how the link is configured to understand if the two configurations are matching.
Config on ports 7 and 8 should still work with my suggested config but the problem with hp procurve could sit at layer 2 and so changing at layer3 can be not effective to solve.
Hope to help
Giuseppe
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