A tag for questions related to Cisco's Catalyst line of switches.
6
votes
3answers
217 views
Traffic Policing
I know traffic policing isn't something that you normally find in a LAN environment, and I wish I wouldn't be finding it in mine. That being said... I have no choice.
The device is a 3750X. The ...
12
votes
3answers
409 views
What happens when 2 computers transmits at the same time to a 3rd one in a full duplex switch?
Consider the following scenario:
I have 2 PC's (PC1 and PC2) that wants to transmit at the same time to PC3 in a full duplex ethernet switch. Let's consider that all ports are in the same VLAN, so ...
5
votes
3answers
121 views
ISR routers - difference between routed and switched ports
On a Cisco ISR router - would you say there are any benefits from purchasing an HWIC or EHWIC to connect to the next set of switches within the branch network?
For instance. Lets say Gig0/0 and ...
8
votes
3answers
154 views
DHCP assign IP address based on MAC address with Cisco CE 500 platform?
I have very little knowledge about CISCO and its switches, but now I have to configure it myself.
Is it possible to allot IP address based on MAC address on CISCO CE 500 (Cisco Catalyst Express ...
5
votes
1answer
60 views
CISCO 4500R+E, Sup7L-E redundancy: RPR or SSO?
We are going to deploy 4500R+E chassis with two redundant supervisors Sup7L-E.
All ports in chassis - switchport with trunks. L3 interfaces - SVI. Chassis wll terminate L3 domain (route between ...
15
votes
3answers
311 views
Accidentally Removed Allowed VLANs from Cisco Switch Dot1Q Trunk
I am adding a new VLAN to an existing trunk port between two Cisco Catalyst switches (3750's). In the process of adding the new VLAN, it appears that I've removed the existing allowed VLANs on the ...
9
votes
8answers
1k views
How do you convince management that 3560/3750s are a bad idea in your DC?
3560/3750s have small buffers and make good wiring closet switches. However I very often see these switches sitting in DCs. Lots of folks tend to use them as they are generally 1Gb and L3 capable.
Is ...
0
votes
1answer
110 views
Why doesn't my port-channel interface come up, between Cisco Catalyst switches?
To connect two Catalyst switch stacks, I use EtherChannel, i.e. I aggregate several ports on each switch to get more bandwidth and higher availability than with just a single port.
However, the link ...
5
votes
2answers
125 views
3750G Switch Buffer Monitoring
We have put some 3750Gs in a stack for our DC access switches. We are concerned that these won't be able to handler higher data loads as traffic increases due to their limited buffers. What ...
6
votes
4answers
89 views
Switch interface config for IP Phones
I have seen both of the following methods of switch interface configuration for supporting IP Phones.
switchport access vlan <data-vlan>
switchport voice vlan <voice-vlan>
switchport ...
4
votes
4answers
111 views
Cisco Catalyst 4500E - modules installation
I have the following questions on Catalyst 4500E hot-swappable hardware components;
Is it possible to insert/pull out line cards to or from powered on chassis?
Is it possible to insert redundant ...
4
votes
2answers
75 views
Cisco active/standby FWSM pair went active/active after switch upgrade
PROBLEM:
Both FWSM in our core switches went active/active and protected subnets have partial accessibility.
SETUP:
We have 2 x Cisco Catalyst 6509 switches running IOS version 12.2(18).
Each ...
21
votes
19answers
3k views
How can I see which switchports are not in use?
On a large Cisco Catalyst switch stack, almost all switchports are patched. I need to identify the ports, which are not in use, for connecting further devices.
Following switchports, cabling, patch ...
9
votes
3answers
285 views
How to find the port a device is connected to, based on IP, on a Cisco Catalyst switch
On a Cisco Catalyst switch, I need to find what port an end device is connected to.
I have the IP address/host name.
How do I quickly find the port?
6
votes
2answers
135 views
Netflow differences between IOS 12.2 and 15.1
Has anyone upgraded their cisco routers from 12.2 to 15.1? I'm curious to know what kind of changes were made to netflow. Most specifically, I'd like to know how (if at all) the CPU utilization ...
3
votes
2answers
88 views
Cisco Catalyst cluster heartbeat switch issue - increasing input errors
PROBLEM:
The servers in two clusters keep losing heartbeat connectivity with each other thus causing database outages. Outages are brief but disruptive.
SETUP:
There are two clusters of three ...
5
votes
3answers
118 views
Using Fabric on a Cisco device : “Line has invalid autocommand”
I wasn't sure where to ask this but it seems to be something on the switch side so I thought I would start here first.
I am working on a little project to automate updates to config files in bulk ...
9
votes
4answers
124 views
Overcome 2 monitor session limitation in Cisco VSS
Is there a way to overcome Cisco's 2 monitor session limitation on a VSS 6500 without the use of a network tap?
8
votes
2answers
156 views
catalyst 3750x - jumbo frames on svi
I've encountered a problem on a cisco ws-c3750x-48ts-s where jumbo-frames won't cross a trunk-connection between a vwmare esx-host and the switch.
The access ports in the same vlan don't experience ...
5
votes
3answers
129 views
Can I run FCoE over Cisco Catalyst 5500?
I have 2 spare older Cisco Catalyst (not Nexus) 5500 switches. Would I need any additional hardware in order to run Fibre Channel over Ethernet (FCoE) over them? Do I need some kind of management ...
5
votes
2answers
168 views
What are the alternatives to OTV for stretching a layer 2 network across 2 datacenters?
We want to find a "safe" way to stretch layer 2 network across 2 data-centers, and since we don't have any equipment running NX-OS on either data-centers we can't use OTV.
So what are the alternatives ...
9
votes
5answers
334 views
What causes total output drops on a cisco switch interface?
I have an HP c7000 blade chassis which contains Cisco 3120X and Cisco 3120G switches running ios 12.2(58)SE1. The blades themselves are very lightly loaded yet many interfaces on different blade ...
9
votes
2answers
117 views
How can I verify QoS DSCP marking on a Cisco Catalyst 4500E?
Good afternoon,
I've got a shiny new 4500E running 15.0(1r)SG7 that is set to replace an ailing 3750E.
It is running ipbase for now.
On the 3750 I was able to check out the incoming DSCP/CoS values ...
11
votes
3answers
132 views
What is the difference between all the switching modes on 6500/7600?
On one of my routers, I see the following switching modes:
#show fabric switching-mode
Global switching mode is Truncated
dCEF mode is not enforced for system to operate
Fabric module is not ...
11
votes
4answers
513 views
Can I use a Catalyst 2960-S for iSCSI?
I need to set up a modest iSCSI SAN with a few ESX hosts and one storage array. Can I get by using a Catalyst 2960-S or do I need to upgrade? Are there any special tweaks I need to make to the switch ...
13
votes
4answers
242 views
Troubleshooting “Down BGP” connections
Our network experienced a short outage when one of our BGP routes went down for a short time yesterday. Thankfully our connections failed over to our secondary BGP route after a few minutes, and the ...
