Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

connections on routers

We are working on capacity planning for some of our sites. These employ Cisco 7606 router. Is there a way to know the current no. of connections being used up. Any specifications which indicate what will be the maximum connection limit on these.

All help is appreciated. Thanks in Advance!

5 REPLIES
Hall of Fame Super Silver

Re: connections on routers

Hello Sunny,

a list of ports active and up/up can be get with

sh int sum | inc ^\*

example:

sh int sum | inc ^\*
* Vlan1                    0     0    0     0  5000    0     0    0    0
* Vlan8                    0     0    0     0  7000    1     0    0    0
* Vlan9                    0     0    0     0     0    0 422000  510    0
* Vlan11                   0     0    0     0     0    0 1210000  262    0
* Vlan13                   0     0    0     0  2000    1     0    0    0
* Vlan14                   0     0    0     0     0    0     0    0    0
* Vlan15                   0     0    0     0 12000    0     0    0    0
* Vlan20                   0     0    0     0     0    0 172000   12    0
* Vlan22                   0     0    0     0     0    0     0    0    0
* Vlan24                   0     0    0     0 30335000  6584 51125000  6339    0
* Vlan50                   0     0    0     0 766000  465 1301000  815    0
* Vlan51                   0     0    0     0 968000  587 506000  297    0
* Vlan99                   0     0    0     0     0    0     0    0    0
* Vlan333                  0     0    0     0 15000    2  3000    1    0
* Vlan617                  0  1785    0     0 31017000  3625 15374000  2157    0
* Vlan618                  0     0    0     0 25711000  3291 10461000  1840    0
* Vlan899                  0     0    0     0  6000    1     0    0    0
* Vlan900                  0     0    0     0 10000   16 184376000  38624    0
* GigabitEthernet1/2       0     0    0     0     0    0 1196000  266    0
* GigabitEthernet1/4       0     0    0     0 16883000  2599 4886000  1112    0
* GigabitEthernet1/6       0     0    0     0 168000  171 243000  160    0
* GigabitEthernet1/9       0     0    0     0 213366000  30962 32972000  6707    0
* GigabitEthernet1/10      0     0    0     0 30000   24 75940000  14454    0
* GigabitEthernet1/14      0     0    0     0     0    1 1827000  847    0
* GigabitEthernet1/15      0     0    0     0     0    1 1825000  847    0

[ truncated ]

Hope to help

Giuseppe

New Member

Re: connections on routers

Thanks, this is also something i didnt knew.

But my query was more on a point where we need to know how many connections are flowing through the device and the maximum that was reached.

Similar to what we have in firewalls, where we have a limit and then we can view the counts for these connections.

This is also to be used for another device with an integrated cisco IOS based firewall.

Thanks for your help in advance!

New Member

Re: connections on routers

Hello

If u have enabled netflow, you can check with show ip cache flow to see the active flows on the netflow enabled interfaces.

Hall of Fame Super Silver

Re: connections on routers

Hello Sunny,

for firewalls we can measure the performance in terms of max sessions and max session rate served (sessions/sec) that can be handled because a firewall inspects each TCP session that attempts to go through and has to build a stateful entry for it (if stateful).

For a C7600 acting as a router the number of TCP sessions that are going through is not really important: traffic is switched at OSI L3 and the router does not suffer from the number of TCP sessions but it is more important the traffic volume and the potential for oversubscription in each linecard.

The only aspect where the number of distinct flows counts is in the netflow accounting: there are limits in the netflow local table size and the more flows are seen the more accounting  packets should be exported.

Depending on the supervisor in use you can face scenarios where the system is able to foward a given level of  traffic with no problems but traffic variety (n. of traffic flows) is so big that the system is not able to account for all flows and there misses in the netflow accounting.

With this kind of device, aa multilayer switch,  this is a possible scenario.

So from a performance point of view the number of connections on a router is not a parameter used to characterize it: you can use packet per second and traffic rate.

You should use the datasheets for supervisor and linecards to understand if you are near any limit or beyond.

Hope to help

Giuseppe

New Member

Re: connections on routers

Thanks for the good explanation. It helped me understand things better.

Now in case if the router comes with an integrated zone based firewall, is there a way to check the same on this.

Thanks a lot!

222
Views
4
Helpful
5
Replies