Used for questions about the commands for Cisco devices.
4
votes
2answers
136 views
“transport input” for AUX port in Cisco routers
On physical layer AUX port works on asynchronous serial RS-232 protocol. However, one can specify various application layer protocols like telnet or SSH as allowed input protocols under AUX line ...
1
vote
2answers
70 views
List ports which do not have a given property
What would be the easiest was to accomplish this?
Find all ports that do not have 'switchport port-security'
show run | exclude ?
I don't have a swicth with me and packet tracer does not have the ...
2
votes
1answer
60 views
Order of entries in “show ip bgp x.x.x.x”
Router# show ip bgp 10.3.3.3 255.255.255.255
BGP routing table entry for 10.3.3.3/32, version 35
Paths: (3 available, best #2, table default)
Multipath: eBGP
Flag: 0x860
Advertised to update-groups:
...
0
votes
0answers
36 views
Etherchannel cisco 881 on FastEthernet ports
Is it possible to configure some kind of etherchannel (port channel) on a cisco 881 with FastEthernet ports? If I try this, the command is unknown.
Setup:
Cisco 881
HWIC - FastEthernet 0 - 3
with ...
-2
votes
1answer
62 views
Simple Ways to Protect CISCO Network [closed]
was looking at some blogs and wanted to ask, what are some simple and obvious configs that one should add to their CISCO edge router to protect the network from network related malicious activities ...
0
votes
1answer
66 views
Route Maps Policy Multiple Interfaces
I have 1 cisco router 3945, i configure 2 gigabit if 0/1 and 0/2, below the if 0/2 i have many sub-if (vlans), linked to a same number of route maps and acl's to make the router send the packet to a ...
0
votes
1answer
66 views
what is the correct syntax for denying tcp connections to a subnet (cisco)?
Is
deny tcp any host 1.1.0.0 0.0.255.255
correct,when I want to block access to the 1.1.0.0/16 subnet for any host on the LAN?
2
votes
1answer
221 views
Cisco ASA 5550 stuck on boot from tftp
I have a cisco ASA 5550 firewall. I lost my image.
I tried to boot from tftp using rommon to upload new image but it doesn't work, now i want to get back to boot from flash but i'm stuck with the ...
4
votes
2answers
386 views
SNMPv3 Setup - Cisco 3750
I am not a network guru by any means but need to setup our router/switch to use SNMPv3. I am installing What's Up Gold on our system and configured the settings (changed for this post) as follows:
...
1
vote
1answer
126 views
Listen-only (stealth) CDP on IOS
I would like to put my router in a listen-only mode for CDP i.e. it should allow CDP packets to only arrive while not advertising so that I can glimpse into physical topology while remaining hidden to ...
1
vote
0answers
75 views
disable cdp on multiple sub interfaces from physical bearer
you can enable flow on the physical bearer and it will automatically add the flow configuration to any subsequent sub-interfaces using "ip route-cache flow"
is there any way to disable / enable cdp ...
3
votes
0answers
159 views
Enable traps on FIB (Forwarding Table) changes
I've been working for weeks to enable sending traps for FIB changes on our Cisco 2600 router. I finally found this command is responsible for that:
snmp-server enable traps cef peer-fib-state-change
...
1
vote
0answers
321 views
Alternative command to show interface status [closed]
What is an alternative to using the command show interface status on a switch?
I am using packet tracer to do some simulations and I am not able to use this command while in PT.
I realize that this ...
3
votes
1answer
7k views
Cisco Router Telnet Connection Refused
I have a cisco 1941 router just configured but no matter how I go about configuring the telnet, it seems not to work.
It has interfaces already set up and systems can browse through it in the ...
0
votes
1answer
212 views
Show interfaces link equivalent [duplicate]
On Catalyst 4500, there is the command show int link which outputs:
Fa1/1 UPS 00 secs
Fa1/2 Data & Voice 00 secs
Fa1/3 Data & Voice 00 secs
...
2
votes
2answers
1k views
Show connected (up) interfaces on cisco devices
Is there any way to show a total count of interfaces that are in status "up" on a cisco router?
The purpose is to let a script go through all routers and show a summarization count of "up" ...
-1
votes
1answer
746 views
How do I enable a DHCP server on a Cisco Aironet 1250 series or 1260 series AP?
I need to enable or disable the DHCP service on one or both of the Cisco APs in the title (well any Cisco AP if there is a standard method), running on running RHEL v15 or v16.
I would very much ...
4
votes
1answer
185 views
“Protected” switchports on a Cisco 881W
I want to configure a Cisco 881W to deliver Corporate wired and wireless connectivity, plus Guest wireless connectivity on a second SSID, connected to the core by a site-site VPN. I was expecting to ...
1
vote
1answer
250 views
Creating multiple trunk ports on a Cisco ME3400
I have a cisco ME 3400 switch . And I have configured fa0/23 as trunk port and connected this to a router for carrying multiple vlan traffic. And i have created some vlans eg: 1500, 1501 etc and added ...
2
votes
1answer
190 views
Cisco router dot1Q monitoring
How can I monitor on a Cisco router if dot1Q packets arrive on the trunk interface or if others arrive on that interface (like ISL, the old protocol of Cisco)?
How can I do this and what is the best ...
4
votes
1answer
2k views
time based interface shutdown on cisco router
Is there a way to shutdown an interface on a Cisco router based on time periods?
I would like to shut the cellular interface when it is not necessary.
Can this be done with the event manager and ...
8
votes
1answer
1k views
QoS between two VLANs with Cisco 881 Router (IOS)
I'm hoping to get some advice regarding the best practice to delegate a limited Internet connection between two VLANs. In my case one VLAN is for an office network, and the other is for guests. What ...
3
votes
1answer
1k views
Enabled VPN — Site to site — Cannot access internet now .. Cisco ASA 5505
I had just enabled site to site VPN access ... I am assuming something got messed up with NAT ... It's the strangest thing .. I cannot find anything wrong through ASDM, or CLI .. Yet, I can ...
6
votes
2answers
978 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 ...
5
votes
4answers
8k views
Reconfiguring Layer3 Switch to enable IP routing and become the default gateway
Current configuration with HP Procurve 2848 switch at a colocation facility consists of using the ISP switchport as the default gateway. The current configuration is very basic with only 1 vlan assign ...
6
votes
1answer
3k views
About the inside local and outside local and inside global and outside global
I have some concept problem with the NAT. Here is the Cisco definition for the local and Global and the NAT operation.
Local address—A local address is any address that appears on the inside ...
5
votes
1answer
1k views
Chassis temperature and Fan status on Cisco 3548 switch
I need to remotely check the status of the fans and temperature of a switch that I currently do not have physical access to. I have done so in the past on a 2950 with the command:
Show environment
...
7
votes
1answer
2k 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 ...
6
votes
2answers
2k views
SNMP and Syslog in configuration
Really stupid questions guys so I apologize. When sending Syslog messages to a server we use the command logging x.x.x.x. I get that part.
SNMP is used to gather stats or change configurations on ...
12
votes
2answers
5k 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 ...
6
votes
2answers
2k views
Configuring redundancy using floating static
I wanted to post my network layout, but I dont have the required reputation. So I have made up a network diagram below:
ISP
/ \
/ \
/ \
HQ------Branch
| ...
4
votes
1answer
460 views
How do I create an SSL CSR via CLI for Cisco Prime?
I'm trying to create a csr for a cisco prime server.
I managed to create a csr and put it in the "defaultRepo", which is local on the disk. After what I've read I need to create a certificate repo ...
8
votes
11answers
2k views
Locate a host on Network
What is the best method of locating a particular workstation on a VLAN ?
I sometimes need to do this, if a workstation IP address, shows up on an ACL Deny
torrent use
High bandwidth usage (Top ...
12
votes
1answer
829 views
BGP “no synchronization” command not showing up in running-config
I noticed in the running config I don't see the no synchronization command under the BGP section. Is this a default command so I won't see it unless I change it?
Hardware / software
Cisco 1921
...
3
votes
2answers
1k views
OSPF LSA Refresh Time
Is there a Cisco command that would allow one to modify the default value of 1800 seconds (30 min) for the OSPF LSA refresh rate?
1
vote
1answer
101 views
How can I log authentication errors in 3G routers?
What command (debug) can I use to see authentication errors on a cisco 3G router specifically for the 3G connection?
18
votes
3answers
8k 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
2answers
2k views
6
votes
3answers
328 views
Why does “show adjacency” take so long to run?
Why does the "show adjacency" command take so long to run (in the order of minutes) on Cisco IOS Software, 7200 Software (C7200P-SPSERVICESK9-M), Version 12.4(4)XD5, RELEASE SOFTWARE (fc1)? The ...
9
votes
5answers
1k views
How can I speed up CLI typing in Cisco IOS using shortcuts?
I know we can use auto-completion (tab key) and abbreviated commands (such as sh ip int bri) to speed up typing.
However, I'm still not satisfied with typing crypting chains such as sh ip dh sn bi | ...
4
votes
1answer
1k views
Cisco 867 forward UDP port range
I need to forward an UDP port range to a specific private IP address in my LAN.
In order to forward one port to an internal IP I do:
access-list <acc_list_number> permit <port_type> any ...
7
votes
1answer
12k views
Cisco config example for Policy Based Routing
I find my self in a situation I was in not too long ago, but I can't
remember how I resolved it :)
The Scenario
I have a Cisco IOS router with a LAN interface (fa0/0) and a WAN
interface (fa0/1), ...
9
votes
1answer
230 views
Deconfigure an interface in IOS with one command
I was wondering if there is a single command to clear a single network port's configuration? (wipe switchport, portsecurity,...)
8
votes
3answers
6k views
Cisco: prevent vlan's of communicating with eachother on cisco router (ACL alternative)
Setup: Cisco router with multiple VLAN's configured on it.
How can you prevent 2 VLAN's communicating with eachother? Normally I would do this with ACL's like this:
access-list 102 deny ip 1.1.1.0 ...
8
votes
5answers
5k views
Monitor specific traffic type on a Cisco router
Is it possible to monitor a specific traffic type going through a cisco router? (like monitoring via wireshark)
Ex: I want to monitor http traffic specifically that is passing through a router. (or ...
3
votes
2answers
1k views
Cisco: No autostate on GigabitEthernet interfaces, any alternative? (not working)
I recently tried the command "no autostate" on a GigabitEthernet interface (on a newer router) and this didn't work anymore, does anyone know why this is occuring? This use to work on FastEthernet ...
8
votes
1answer
2k views
PPPoA ADSL Configuration with external modem on Cisco 891
Context
We use Cisco 891 routers as CPE for several client sites. They are all running IOS 15.
Cisco IOS Software, C890 Software (C890-UNIVERSALK9-M), Version 15.0(1)M8, RELEASE SOFTWARE (fc1)
The ...
27
votes
23answers
21k 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 ...
11
votes
5answers
35k views
How can I reset a VPN tunnel on a Cisco ASA?
On a site-to-site VPN using a ASA 5520 and 5540, respectively, I noticed that from time to time traffic doesn't pass any more, sometimes just there's even missing traffic just for one specific traffic ...
