Questions tagged [cisco-ios]

For discussion about Cisco's Internetwork Operating System - Cisco IOS

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Cisco IOS CLI — Difference between global configuration and console line configuration mode (using line console 0 command)?

Student here. Could someone please explain to me the difference between these two? I'm using a serial connection for this. Does the latter refer to one individual serial terminal session? Why would ...
3
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2answers
7k views

Cisco Command to display link status

I am having a bit of a brain freeze. I would like to know the command that displays the link status when a network cable is unplugged from the switch port. What is the command name?
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2answers
158 views

Client timeout for Cisco IOS Static DHCP Pool

I'm not a network admin, but I have an old Cisco Catalyst 3560 for my network. I've successfully set up a DHCP Pool: ip dhcp pool 192.168.0.0 network 192.168.0.0 255.255.255.0 default-router 192....
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2answers
772 views

No passive-interface error

I'm trying to nest some EIGRP configurations on a router in GNS3. I'm trying to connect the EIGRP 2801 in SW01 to RTR-01 and EIGRP 2864 to RTR-02 when I do. When I put no passive-interface ...
3
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2answers
3k views

Editing startup-config

I have a Cisco router, and I want to remove a few lines from startup-config. How could I do it? Do I need to copy it over to a PC, edit it there, then copy it back, or can I do it through the serial ...
3
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2answers
100 views

Firmware Compatibility with 15.x IOS versions

I have a Cisco switch stack with both PoE and non-PoE switches as members. Is there any compatibility issues with the firmware version 15.0.2-SE11 between the following devices? 1x Cisco WS-C3750G-...
3
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1answer
552 views

Fix our Cisco switch overwhelmed by console logging

I have a setup with dual redundant Cisco catalyst 4506-E using the WS-X45-SUP8L-E supervisor engine and two 48-port switches below it. My task is to access and modify the switch configuration. ...
3
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2answers
221 views

Converting a Cisco 827 for FTTN NBN

I have a customer who is moving to NBN in a few months and I thought I would start to look at the config changes now when there is no time pressure. I assume I will have 2 options: Change the ...
3
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2answers
2k views

How do I determine how many routers are in an OSPF area?

Is there any show command which allows me to determine the number of routers in a specific OSPF area? I can use the show ip ospf database router command and consider each LSA represent one router, but ...
3
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1answer
698 views

Cisco IOS Extended Access List changes destination network to 0.0.0.0

I am trying to create named extended access-lists on Cisco IOS on an 800 series router, but it changes the destination network to 0.0.0.0. Example: ip access-list extended ACL-TEST permit tcp ...
3
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2answers
742 views

Cisco 2600 IOS ICMP packets viewing

Does anyone know how to view ICMP packets (ping), if possible, traversing through a Cisco 2600 router, that is, how to use the console connection to the router (the usual for configuration) to display ...
3
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2answers
5k views

Configure spanning-tree on Cisco router

I have seen spanning tree being configured on switches to prevent switching loops. I recently noticed that show spanning tree command works on a Cisco 1841 router as well. For what reasons would we ...
3
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1answer
3k views

Easy PVST to MST transition

I have a scenario of six switches (C2960S, Version 12.2) running out of PVST instances so a transition to MST is inevitable. Seeing how small scale the setup is, I assume I could shut a few links to ...
3
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2answers
173 views

Decreasing SNMP update timer on IOS-XR (CISCO ASR)

I've a case where i'm trying to poll SNMP information every 10 seconds from a Cisco IOS-XR devices (interfaces mib). Seems like CISCO IOS-XR updates SNMP information every 15secs, so sometimes ...
3
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2answers
7k views

Cisco: err-disabled due to loop - but there are NO redundant physical paths/ wires/ connections

for the third or fourth time in approx two years we have (painfully) noticed some really strange (at least to us) behaviour in our datacenters: Uplink-interfaces on access-switches which have only ...
3
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2answers
23k views

Command associations with privilege levels in Cisco IOS

As I understand, by default, IOS has three privilege levels: 0, 1 and 15. Privilege level 0 has six available commands: r1>? Exec commands: <1-99> Session number to resume disable ...
3
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1answer
1k 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 ...
3
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1answer
964 views

IOS for Cisco 6509/7609

Good morning, I need to move one SUP7203bXL from a 6509 chassis to a 7609. Now the SUP has the IOS: s72033-adventerprisek9_wan-mz.122-33.SXJ.bin I would like to have the IOS: c7600s72033-...
3
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1answer
406 views

CSCvg76186 - Cisco Smart Install Remote Code Execution and Denial of Service Vulnerability

If you missed this Catastrophic severity 1 vulnerability, check the temporary solution below, if you do not want to upgrade your software to a not properly tested software. There are currently, at the ...
3
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1answer
124 views

How to permit behaviour in Cisco access-list commands?

If a host on a network is permitted to access another host on a different network via an ACL on the source host's router, does that automatically deny other hosts on the same network as the source ...
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3answers
4k views

How to find my public IP within IOS?

I have access to a router. I want to know its internet IP address through its ISP. I thought about using ifconfig.me but it won't let me. #copy http://ifconfig.me/ip flash:ip.txt Destination ...
3
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2answers
3k views

Access rule that permits NTP response

Nagios is used from HOST1 to check the NTP server on HOST2. One of the servers resides in an ACL. The assumption was that ip access-list extended vlanX permit udp host HOST1 X Y eq ntp deny ip ...
3
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1answer
1k views

Troubleshoot SNMP - NPEG2 - Purpose of snmp mib community-map <community> engineid command

we have several cisco 7225 vxr deployed on our network and we have an issue on SNMP access. On last new deployment, we can't reach the last router implemented through SNMP. Comparing two router with ...
3
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1answer
2k views

Junos feature to accept multiple BGP paths from multiple peer AS

Cisco IOS provides this hidden BGP command: router bgp <ASN> bgp bestpath as-path multipath-relax It allows the router to install multiple BGP prefixes with distinct as-path'es (but ...
3
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1answer
1k views

Forcing Cisco DNS relay to send requests from behind PAT [closed]

I have a Cisco 1811 configured with PAT: interface FastEthernet0 ip address dhcp ip nat outside interface Vlan1 ip address 192.168.0.1 255.255.255.0 ip nat inside ip nat inside source ...
3
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1answer
444 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 ...
3
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1answer
954 views

How to setup a WAN port in Cisco ISR 1111?

The C1111-8p has 2 WAN ports and 8 switch ports. I am trying to set up the WAN port to an optical fiber modem, the ISP provided: IP address Mask Gateway DNS1 and DN2 I need to set up the port GE 0/0/...
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1answer
1k views

Cisco QoS SRR Share & Shape impact

I am working on understanding the impact of using shaping and sharing with the SRR scheduler. Given these 2 commands on an interface: switch(config-if)#srr-queue bandwidth share 40 20 30 20 switch(...
3
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1answer
172 views

Cisco Router IOS update

I am facing problem in update the IOS of Cisco 7304 router. I am upgrading from 12.4(24)T2, to 15.2(4)S7 this. but I was boot from this version 15.2(4)S7 it booted proper from flash. But when I put ...
3
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1answer
260 views

Set password of a Switch to “C?1sc0” using CLI in Cisco Packet Tracer

I have been asked to set the password of a Switch to "C?1sc0" in Cisco Packet Tracer. The problem is that when i type "?" in CLI it prints out: Router(config)#enable password ? 7 Specifies a ...
3
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1answer
4k views

IPsec Tunnel is showing decrypt packets counter but 0 encryption packets: #pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0

I have just configured the IPSEC tunnel between my router and the Access point.I could see that the Tunnel has came up and Active in both sides. However,When I checked the "Show cyrpto ipsec sa" ,I ...
3
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1answer
748 views

Routing Between VLANs on Cisco 1921

I have setup a new VLAN for VoIP phones that are being installed. I would like to segment their traffic to Subnet 10.20.77.0/24. I added an IP address to the DHCP server of 10.20.77.11 to help serve ...
3
votes
1answer
277 views

Cisco router under workgroup bridge AP

My question is about addressing a Cisco router interface so that I can use both bridging through an access point as workgroup-bridge and also connect to the access point to configure it. Apologies ...
3
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2answers
14k views

show current power consumption Cisco 3650 IOS 3.07.04E

What command can I issue to see the current power (POE and System Power) on a Cisco 3650 Switch running IOS 3.07.04E. Sh Env Power #shows me power supplies, not usage. Sh Power Inline #show me the ...
3
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1answer
795 views

IOS does not respond to NTP queries unless client is in “peer” ACL

I have set up NTP on a Cisco IOS device running IOS 15.2M, and this is my bare-bones config used for testing: ip access-list standard IPV4-ACL-NTP-PEER permit <UP.STREAM.NTP.SERVER> log ! ip ...
3
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2answers
13k views

Cisco IOS — How do I make the console prompt for a password upon serial line session 0 connection?

I'm using Putty to connect via a serial connection to the console. I have a line con 0 password set, as shown by show running-config. I close this session (via Putty), reconnect, and the CLI prompt ...
3
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1answer
689 views

Cisco IOS nat inside not working working after reboot

I have a strange problem - after rebooting my Cisco 867 router running IOS 15.5 all inside NAT translations do not work until I remove and re-establish the access group on the outside interface. I'm ...
3
votes
1answer
400 views

Securing Console Serial Ports

I am looking to secure our console ports in our remote console router equipped with HWIC-16A cards and RS232 cables. As the network admins, we usually login to these routers first (using privilege 15 ...
3
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2answers
5k views

Limit bandwidth in cisco router with policy-map doesn't work

I have a problem with my scenario in limiting bandwidth of ubuntu PC in GNS3 with class-map and policy-map. this is my topology in GNS3: The R1 is a cisco 3725 router with c3725-adventerprisek9-mz....
3
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2answers
5k views

Run out of ideas to troubleshout Ping issue Cisco IOS 3560 Switch

Summary Yesterday, four of the eight systems (connected to same VLAN, identical ethernet adapter settings) were able to ping tweakers.net. Today, another system is not able to ping the internet ...
3
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2answers
54 views

Understanding traffic flow on SVIs [closed]

I have a simliar question to this one: Access-Lists and VLAN and understanding traffic flow But my question is concerning service-policies. Have a look at the image above. I triet to make a traffic ...
3
votes
1answer
73 views

Finding MAC address with OUI List

I'm in the process of labeling the interfaces of my Cisco 3750G with descriptions referencing the device type that is associated with that port. I understand that I am able to run a show mac address-...
3
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1answer
86 views

ip dhcp class command

Here is a DHCP configuration that we have here: ip dhcp class range ip dhcp pool abc network 10.10.10.0 255.255.255.0 default-router ... class range address range 10.10.10.10 10.10.10.254 My ...
3
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1answer
493 views

How to get per-process memory use from Cisco switches via SNMP

I'm trying to get per-process memory use from Cisco switches via SNMP. I've found an article suggesting you can subtract CISCO-PROCESS-MIB.cpmProcExtMemAllocatedRev and CISCO-PROCESS-MIB....
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2answers
1k views

Cisco IOS pick default route from two DHCP interfaces with track

I plan to have a portable IOS cisco router which will have two DHCP assigned ISP addresses from unknown ranges. A tunnel is then built through the preferred ISP to another outer. I would like to set ...
3
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2answers
3k views

sh int transceiver Explanations

When looking at the output of show interfaces transceiver on a Cat 4500X you notice that there is a Tx and a Rx power measurement. My questions about this output are: Why is each transceiver ...
3
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1answer
258 views

Is test etherchannel load-balance disruptive?

Is this command disruptive or just a logical exercise of existing configuration? test etherchannel load-balance int po3 <some mac here> Platform is 6500 series, running IOS. Thank you!
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2answers
2k views

TACACS Implentation server key error

I'm implementing a new TACACS server on our network after having removed the old TACACS server which we no longer own. I've already gotten the implementation working with the NX-OS devices, but when ...
3
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1answer
4k views

Cisco 3560 snmpget OID temperature not found?

I'm working on creating a monitor script for some access layer switches. I've gotten it to work with some Cisco 3750s, but when I try it on a Cisco 3560, it says the OID object not found. After ...
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1answer
4k views

How to setup Cisco IOS with multi public IP's

I'd like to set up a little network environment. We have bought 2 different subnet from our ISP. The WAN internet connection : xx.yy.81.61/26 WAN gateway: xx.yy.81.1 First subnet : xx.yy.81.80/30 (...

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