Last call to make your voice heard! Our 2022 Developer Survey closes in less than a week. Take survey.

Questions tagged [cisco-ios-12]

Major release 12 of Cisco's IOS software

Filter by
Sorted by
Tagged with
0 votes
2 answers
32 views

using Cisco WIC-4ESW 4PORT ETHERNET WIC Card (L2 switching card) on a 1700 Cisco router, where the router stores the MAC address of connected devices?

Router is an L3 device, but some models (such as Cisco 1700 router), we can attach the WIC-4ESW which is L2 switching card. as per the offical Cisco datasheet: The WIC-4ESW interface card is a Layer 2 ...
user avatar
3 votes
1 answer
1k views

Moving from 12.x IOS to 15.x IOS - Cisco 3750G

Is there any issue with jumping from IOS version 12.2(35)SE5 to 15.0.2-SE11 on a Cisco WS-C3750G-48PS-S switch? Should I upgrade to the latest 12.x first (12.2.55-SE12), and then move to the 15.x ...
user avatar
  • 671
1 vote
2 answers
82 views

Old 2611 and desired features

I just recently got my CCNA and bought some routers from the teacher that he had laying around to do some home labbing. While two of them are good and more modern, the third one is an old 2611 from ...
user avatar
3 votes
1 answer
6k views

What is the Cisco IOS 12 "Ctrl +C" Key sequence to Break an operation

I screwed up and didn't configure a router for "no ip domain lookup" and then inadvertently pasted a slew of commands into Hyperterminal and now my session is cycling through a gizillion domain ...
user avatar
2 votes
2 answers
3k views

Cisco IOS Switch: Why is "no spaning-tree vlan XXX" automatically inserted on vlan creation?

Yesterday we added a few VLANs (218-220) to one of our core-switches (WS-C3560X-24, c3560e-universalk9-mz.122-55.SE3 running as vtp-server) and noticed that a configuration directive no spanning-tree ...
user avatar
1 vote
1 answer
1k views

How do I upgrade the IOS for a couple of Cisco Catalyst 3500 Series XL 48 port switches (via CLI)?

How do I find the correct (.bin?) file on the Cisco website? I searched for "C3500XL" (from the show version output as shown below) and was presented with Cisco Search Results ... but the links don't ...
user avatar
1 vote
2 answers
9k views

Reserve an IP for client on Cisco DHCP server

So I thought I knew how to set up my DHCP Server on my 3550 switch and reserve IP's for clients. I go into the pool I need to reserve the IP in, but I do not have the address command as an option to ...
user avatar
  • 403
4 votes
2 answers
521 views

IOS upgrade - pair of WS-C6509-E

I've got a pair of WS-C6509-Es, and it's time to upgrade their IOS. They have been up for 5 years, so I have some concerns if they will boot up after reboot - I would like to ask your opinion if any ...
user avatar
  • 75
1 vote
1 answer
79 views

Cisco 9971 connected to Cisco 3550

I have a Cisco 3550. I wanted to connect a 9971(used) to it, but it is not going beyond POST. I see the keys blinking but nothing happens after that, and this happens in a loop. Could that be a ...
user avatar
  • 536
3 votes
4 answers
1k views

Syslog severity level to 5 + ACL BLOCKED log

I am on a L3 switch C3750 IOS 12.2 and I want to log in the buffer (or just to the syslog server) all severity 5 messages and just the ACL Blocked level 6 messages. Is there a way to do this ? I've ...
user avatar
  • 180
2 votes
1 answer
6k views

Configure SSH cipher on Cisco IOS 12.2(55)SE7

Today a customer contacted me because he has upgraded his MacBook to MacOS X Sierra and since then, when trying to access a switch via SSH he got the message Unable to negotiate with 10.XX.XX.XX ...
user avatar
  • 18.3k
3 votes
1 answer
127 views

qos for Cisco VPN

i am trying to configure QOS for site to site VPN, i want to dedicate 50% of the bandwidth on the physical interface to VPN traffic, then the remaining to internet traffic. the connection to intranet ...
user avatar
  • 31
2 votes
2 answers
354 views

Cisco IOS: ACL on local interface

Is there a work-around to apply an ACL to packet originated by the router itself? How do I block certain packets not forwarded but sent by the router matching the ACL? I do not want to solve this ...
user avatar
1 vote
1 answer
5k views

Cisco Static NAT with DHCP outside interface

I'm working on a Cisco 2800, trying to get it to NAT an internal RFC1918 to a WAN. The WAN (ISP) address is from DHCP. I've never worked with NAT on a Cisco before. Cisco's tech pages are also listing ...
user avatar
7 votes
4 answers
24k views

Access-Lists and VLAN and understanding traffic flow

I have a question that I am having a very hard time wrapping my mind around, and I think you might be able to square me away. When applying an access list to a VLAN interface (VLAN 32) in a L3 switch,...
user avatar
  • 443
6 votes
2 answers
4k views

Switchport BPDUs dropped at ASA firewall

I have stacked 2960X switches trunked to a single ASA 5515X in routed mode, and I've captured the drops with capture voip type asp-drop l2_acl after seeing the l2_acl counter incrementing in show asp ...
user avatar
6 votes
1 answer
2k views

Rate limit specific Cisco ISR syslog messages

We have a bunch of ISR 2800s on 12.4(25b) that basically are in production until they die. There are no plans to invest money in SmartNET or purchase replacement fans. We are getting a ton of fan ...
user avatar
4 votes
2 answers
22k views

SNMP: Configuring/Enabling SNMPv3 on Cisco IOS and SNMP Agent

I have been configuring and using SNMP v2c on Cisco routers. Due to the obvious advantages in SNMP v3, I am planning on enabling SNMP v3 on SNMP v3 supported devices. Could someone let me know: The ...
user avatar
  • 601
3 votes
1 answer
160 views

How are edits applied to a `running-conf` when using Cisco CP's "Configuration Editor"?

The Cisco Configuration Professional 2.5 User Guide PDF doesn't say much about the Configuration Editor tool except, "For information about how to use Cisco CP to work with the Configuration Editor ...
user avatar
  • 133
6 votes
2 answers
2k views

Devices that utilizes CISCO IOS Operating system

I am a bit confused about the CISCO IOS operating system. My final year research project is based on solving some security vulnerabilities that i dug up that exists in the CISCO IOS, thus i need to ...
user avatar
3 votes
1 answer
4k views

OSPF between ASA and IOS: Subnet and area design

Network: 100.10.0.0/21 R1, 100.10.0.9/29 (loopback 100.10.0.1/32) R2, 100.10.0.10/29 (loopback 100.10.0.2/32) ASA (active), 100.10.0.11/29 ASA (passive), 100.10.0.12/29 R1 has two bgp transit ...
user avatar
  • 171
6 votes
0 answers
686 views

VirtualAccess Behavior with PPP

A small ISP I provide service for has recently been consolidating their equipment. One of their small branches only has a handful (5 or so) of users receiving their internet through a router, a Cisco ...
user avatar
7 votes
2 answers
3k views

"Local Policy Denied Prefixes" in 'show ip bgp neighbor' output

I've been spending the last week or so troubleshooting some (maybe related, but probably not) issues with Quagga. I have a test router - 7204VXR-NPEG2 running 12.4(24)T6 - with a single BGP session to ...
user avatar
  • 8,847
6 votes
1 answer
204 views

Cisco 3620, installing nm-2fe2w

Is the WIC plug and play or are there commands that I need to run? The router is not showing the interfaces. I tried using the sh diag and it didn't show anything.
user avatar
  • 61
9 votes
1 answer
9k views

Is 'switchport protected' supposed to block unicast flooding?

Does having switchport protected configured on an interface prevent unicast flooding for a MAC address the switch hasn't learned? The information that I'm seeing conflicts -- the wikipedia page on ...
user avatar
10 votes
1 answer
4k views

Long login delay when cisco device is booted

Whenever we boot or reboot a Cisco router or switch we have to wait a number of minutes before we can get a username prompt for login. We get a few fail messages Press RETURN to get started. % ...
user avatar
10 votes
1 answer
5k views

Cisco IOS: Show ip route output order

I am runing some BGP tests through the lab before rolling them out in production (thus, any IP addresses or AS numbers etc used here are done so in a completely fictitious manner). Something that has ...
user avatar
  • 5,270
11 votes
1 answer
9k views

How do you get rid of deleted sub-interfaces from NVRAM?

This is more of a cosmetic issue however it does bug me.... I removed the sub-interfaces off a 3845 router by issuing. no int fast1/0.10 no int fast1/0.15 default int fast1/0 When I do a show run......
user avatar
  • 2,527
17 votes
2 answers
34k views

Cisco - display ALL routes using a single command

In Junos when you use a show route it displays the routing tables , starting with inet.0 ( global routing table) and then listing each VRF in alphabetic order. I am after a similar command , for the ...
user avatar
  • 1,609
16 votes
3 answers
10k views

Backing up Cisco router configuration - including ssh keys

We have some Cisco 2821, 2921 and 1921 routers in our shop. I can back up and restore the configurations by copying out or in the startup-config file, but what about the keys for ssh? I don't want ...
user avatar
18 votes
3 answers
6k views

Writing text to the log

Is it possible to write an arbitrary line of text to the log of a Cisco IOS 12.x device? I should like to be able to put in markers when fetching configs via TFTP and I would like to be able to have ...
user avatar
  • 623
12 votes
3 answers
11k views

1 router, 1 internet connection/IP - multiple VRFs using the same ISP gateway

My knowledge of inter-VRF routing isn't the best. I have one public IP. The public Internet and its quad 0 is on the default VRF.... Then I have a Guest_VRF and a corporate_VRF which would both need ...
user avatar
  • 2,527
4 votes
4 answers
2k views

Cisco 2600 series router logging a lot of "Memory allocation failed" errors

We are getting the below two error messages randomly on a 2600 series router. Syslog shows the router has been fine up until a few days ago. Would a reboot most likely cure the issue or is it most ...
user avatar
12 votes
7 answers
16k views

DHCP relay problem on interfaces secondary network

A secondary network was configured on an interface of a Cisco 2621 router and the ip helper-address commands put in place but no clients of that secondary network could pull DHCP addresses. We swapped ...
user avatar
10 votes
2 answers
4k views

How can I disable SIP on IOS 12.x

How would I disable SIP on an Cisco router running IOS 12.x?
user avatar
  • 103
6 votes
1 answer
6k views

SNMP ENGINE process has high CPU usage on a few 6500 chassis

Four of our 6500 chassis have a constant high CPU usage from the SNMP ENGINE process. Three of the chassis run around 20-30% constantly and the fourth is running around 50% constantly. We have about ...
user avatar
8 votes
2 answers
2k views

Moving internally allocated VLANs

A VLAN I need to use is allocated for internal usage (as per vlan internal allocation policy ascending). I can't (easily) move the traffic over to another VLAN for various practical reasons. I was ...
user avatar
  • 623
10 votes
1 answer
4k views

Configuring HSRP on Nexus OS

How do you configure HSRP on a Nexus 7000 series switch? I know in IOS the commands are in the interface configuration, for example: switch-a#config t switch-a(config)#interface g1/0/1 switch-a(...
user avatar
  • 8,258
24 votes
10 answers
305k 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?
user avatar
  • 8,258
10 votes
2 answers
2k views

Why does my Cisco 6509 BGP table use two entries in my TCAM?

I have a problem on my Cisco 6509, each entry in my BGP table occupies two entries in the TCAM. If I show capacity forwarding, I see MPLS entries in L3 forwarding resources. But, I do not use MPLS on ...
user avatar
  • 103
7 votes
2 answers
960 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 ...
user avatar
8 votes
3 answers
4k 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 ...
user avatar
  • 272
9 votes
4 answers
5k views

Cisco-configuration syntax highlighting for TextMate/Sublime Text [closed]

I would like to have syntax highlighting while perusing my configs - does anybody know of a good Cisco IOS syntax highlighting bundle for TextMate or Sublime Text? Edited (2015-09-21) to add: GitHub ...
user avatar
  • 623
9 votes
1 answer
685 views

TCP Client / Server in Cisco EEM 3.0

I'm attempting to set up client / server sockets in Cisco EEM 3.0 TCL with IOS version 12.4(24)T8 (this was recently upgraded to determine whether the problem was EEM ver). I have the following two ...
user avatar
  • 276
16 votes
5 answers
80k 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 ...
user avatar