Questions tagged [cisco-ios]

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

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Why is it impossible to advertise all OSPF /24 and not all /32 into BGP by using ACLs

For example: advertise all /24s from OSPF into BGP, but not the /32s. Impossible to do with access lists. the above statement can be found in this forum, in a question related to the differences ...
1 vote
1 answer
1k views

Trying to figure out why Serial0/0/0 can't be pinged

Here's the setup: R1 -> R2 | |--> R3 R1 has 2 serial interfaces - Serial0/0/0 (10.0.0.1) is connected to R3 (Serial0/0/0 - 10.0.0.3), and Serial0/1/0 (10.0.0.4) is connected to R2 (Serial0/...
4 votes
2 answers
817 views

After I set the "router rip" networks, how can I check it?

In my CGR1240 I have set network 192.168.1.0 to my router rip, but how can I check it? If I add more networks in rip, how can I list all the networks I have added? I can not show the router rip in ...
2 votes
2 answers
2k views

PC can't ping router 2 hops away (home lab)

To give some context, here is my setup: ----(10.0.0.1 - S0/0/0) R1 (S0/1/0 - 10.0.1.1)---- | | | | ...
1 vote
1 answer
83 views

Access list per port for 48-port switches

We have 3750g, 3750e, 4948, 2960 series Cisco switches and all of them are 48 ports so we want to create one standard access list per port switch and in every ACL we permit 5-6 prefix (short prefixes ...
2 votes
1 answer
962 views

How to prevent IOS sending icmp unreachable with output ACL?

I have an output ACL applied on a WAN interface that permits only 1 IP from going out. interface Cellular0 ip address negotiate ip access-group allow100.98.170.25 out ip nat outside no ip ...
1 vote
3 answers
7k views

Disable DHCP on a 2960x?

I must start this by saying I am quite new to the IT scene. Also, I am very new to cisco switches.. I have been tasked to find out information on disabling DHCP on the cisco, and instead have the ...
1 vote
1 answer
1k views

Which system image should I choose to upgrade my Cisco switch? It has to be a cryptographic image

I have a task to upgrade Cisco switch with a cryptographic image. However, I can't figure out with one I can choose from the list that I have available to me. Please advice. Here is my current switch ...
3 votes
1 answer
7k views

How to erase running-configuration in Cisco IOS-XE?

I am using ASR 9k series Routers, which runs IOS-XE advancedmetroipaccess License I tried erasing NVRAM: and then tried to run copy start run But it gives me error : hostname#erase /all nvram: ...
3 votes
1 answer
257 views

Cisco Route Tagging Question

We have created a network as shown in the topology: The goal is for subnets/networks in LAN_SW to tagged and the tagged networks to be recognized by routers, CPE, PE CORE_P, REMOTE_PE, REMOTE_CPE and ...
2 votes
1 answer
2k views

How to exclude one subnet in RIPv2?

As I understand, when no auto-summary command is used, the network command could include all the interface with IP addresses included in the classful network border defined by the network command. For ...
2 votes
1 answer
877 views

4507r Supervisor engines aren't operating redundantly

The tl;dr : I have two supervisor engines in a 4507r but the standby unit doesn't appear to be ready to perform when the active module dies. On Sunday I had a network problem that appeared to be ISP ...
2 votes
2 answers
3k views

Cisco router - deny access to host on port 8080, allow on 80

I'm designing a network with the following scheme: I have 5 vlans, 3 on S1 and 2 on S3. I'm currently concerned with making access list. Each vlan has a web server that is configured to listen on ...
2 votes
1 answer
2k views

How exactly is "input rate" calculated in IOS "sh int" output?

Cisco IOS routers display input and output bps and pps values for load-interval time period in sh int output. For example here is load-interval set to 30 seconds: C1921#sh int Gi0/1 | i rate 30 ...
-1 votes
1 answer
92 views

I have a Cisco 2921, CIS-3G-ANTM1919D (3G Antenna) is attached to it. Please confirm if this is optimum

psea399#show Cellular 0/1/0 radio history all psea399 03:51:51 PM Thursday Mar 17 2016 UTC 111111111111111111111111111111111111111111111111111111111111 ...
2 votes
2 answers
368 views

How to configure Cisco IOS DHCP client to have a backup IP address?

I want to setup an 881 router such that it gets its IP address via DHCP. But I also want to setup a backup IP address in case it failed to obtain an IP via DHCP. I tried setting secondary IP address ...
2 votes
1 answer
739 views

Show Inventory command on Cisco

Could someone please confirm if 'show inventory' command works on 'IOS (tm) C3560 Software (C3560-I9-M), Version 12.1(19)EA1d'? If no, what is version and upwards do I need this to get it working?
2 votes
1 answer
567 views

Cisco Prefix List Won't Appear in Route Table

I have the following prefix-list configured on our router: ip prefix-list adsvr seq 5 permit 172.30.5.241/32 ip prefix-list adsvr seq 10 permit 134.239.130.143/32 ip prefix-list adsvr seq 15 permit ...
1 vote
1 answer
467 views

Cannot ping internet from host on second subnet

Everything works other than the fact that HOST cannot ping the DNS server or anything beyond Router1. I can ping all hosts and Google from both Router1 and Router 2. Host can ping FE0/1 on Router1 and ...
2 votes
3 answers
3k views

What is a common setting for NetFlow Active Flow Timeout?

What is a common/best practice value for 'active flow time-out' for flow generation from packets. With 'active flow time-out' I refer to the time limit when the current flow (src ip,dest ip, src ...
3 votes
1 answer
322 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 ...
6 votes
2 answers
1k views

Why is Cisco enforcing X:X:X:X::X for link-local addresses when the standard says FE80:/10?

This document shows that you can use one of these options: interface type/number ipv6 address ipv6-prefix/prefix-length eui-64 ipv6 address ipv6-prefix/prefix-length link-local <------...
2 votes
1 answer
711 views

Does Router automatically exclude default-router address from DHCP leasing?

I am confused with what happens to the default router adddress when we are configuring DHCP in the router. I have the network with 253 hosts, 192.168.1.0/24, and I have configured DHCP in my network. ...
10 votes
2 answers
3k views

What do these three options in a Cisco Router NAT configuration mean?

In a standard Static PAT configuration, where one IP:Port combination is always mapped to another IP:Port combination, there are three possible combinations of inside/outside/source/destination that ...
1 vote
1 answer
3k views

Should I use the same Native VLAN for the management traffic network-wide?

I have the native VLAN on my trunk links set to VLAN 10 which is my management VLAN that spans the entire network. We have one WLC and Access Points connected on a trunk link set to native VLAN20 ...
1 vote
1 answer
393 views

How to run SIP phones in the LAN (NAT Overloaded to single IP)?

We have a small office network switch connected to a DSL modem for internet and telephony access. Now we would to extend network to another location in the same building for which I deployed a cisco ...
5 votes
2 answers
212 views

Carrying remote VLAN via 2 routers to the local gateway

I have a serverA (192.168.15.1) from site A and VLAN is 15, however the VLAN 15 gateway is set at site B (192.168.15.254). There are two ISP routers as a metro role to connect each other by subnet ...
1 vote
2 answers
4k views

How can I ping with source option in Cisco Router?

How can I ping with source option in Cisco Router? I have a ISR 4321 Router, I want to ping from a source IP address: Router#ping ? WORD Ping destination address or hostname ip IP echo ...
1 vote
1 answer
323 views

Help with small office setup - Cisco SG350 28 port switch

I have very limited knowledge in Cisco IOS but in a crucial state to setup up a small office network. I have bought 2 Cisco SG350 28 port Layer 3 switch, Switches should be enabled with VLAN and VTP. ...
1 vote
1 answer
364 views

DSCP re-marking on Cisco Switch

I've followed the commands in this post: DSCP trust boundary policy-map MARKDOWN class class-default set dscp ef Interface Config: interface gig 0/1 service-policy input MARKDOWN The ...
4 votes
2 answers
85 views

Routing Table Eligibility

I have an architecture which is that each remote site has 2 Dialer interfaces dialling into a virtual-template core which authenticates the sessions and applies attributes from a RADIUS server. OSPF ...
4 votes
2 answers
1k views

Why the Cisco Router's loopback interface can not be showed up by default?

By default, why the Cisco Router's loopback interface can not be showed up? Router#show ip interface brief Interface IP-Address OK? Method Status Protocol ...
4 votes
2 answers
2k views

Cisco Router GigabitEthernet interface can not add ip address?

Cisco Router GigabitEthernet interface can not add ip address? Router(config)#interface gigabitEthernet 2/1 Router(config-if)#ip add ? % Unrecognized command Router(config-if)#ip add 12.12.12.1 255....
1 vote
1 answer
167 views

Return traffic for nonzone interfaces in Cisco IOS (ZBFW)

I've found Cisco docs to be extremely vague and confusing regarding the appropriate way to configure access policies in Cisco IOS-based zone-based firewall (ZBFW). Say I want to permit ongoing TCP ...
2 votes
3 answers
3k views

Virtual Appliance - Cisco Router

My colleague said that it is possible to virtualize a Cisco router i.e. run the Cisco IOS inside ESXi and it would act like a real cisco router so thus can be used in a light production environment. ...
1 vote
2 answers
88 views

Is it possible to enable DHCP on multiple hosts via Cisco switches or routers? [closed]

I think I know the answer to this, but thought I ought to ask around. When setting up new networks with multiple hosts, like a university computer lab VLAN with 30+ workstations, for instance, is it ...
3 votes
1 answer
718 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....
5 votes
1 answer
563 views

Cisco 3850-24p stable firmware 16.x.x

Have a query towards the 3850 series switches. Currently making a plan to upgrade a few remote sites from old, stable and steady 3650-24ps (eol awhile back) to 3850-24p. Nothing fancy to support, 1 ...
4 votes
1 answer
172 views

CISCO IOS's feature Secure Shell Version 2 Enhancements for RSA Keys

I have a switch C3750V2-48PS with IOS ver. 12.2(55)SE5. I wanted to copy to it public key for the ssh client but I do not have following command available Switch#configure terminal Switch(config)#ip ...
3 votes
1 answer
6k 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 ...
0 votes
1 answer
64 views

Cisco IOS 12.3 - Mysterious NAT - Where is it defined?

I have the following config (IOS 12.3): A.B.C.13 stands for the outside, public IP, bound on interface Fa0/1.52 37.247.X.206 is a public client I am using to test x.x.x.n stands for a random public ...
3 votes
1 answer
66 views

what is the point of making directories in a cisco cli

what is the point of making directories in a Cisco router. I noticed its was kinda like Linux mkdir and all that stuff, but what is the purpose?
2 votes
1 answer
1k views

Assign DHCP IP address on Cisco router interface

Hi, dhcp router is configured with following DHCP settings: ip dhcp pool B network 192.168.1.0 255.255.255.0 default-router 192.168.1.1 ip dhcp pool C network 192.168.2.0 255.255.255.0 default-...
2 votes
1 answer
19k views

how to deny ping from one direction but not the other using Access-list

Hello everyone. What I'm trying to do is to deny ping access from the 12.12.12.0 network to reach the 10.10.10.0 network but not deny ping access to go from 10.10.10.0 network and reach the 12.12.12....
1 vote
1 answer
93 views

Cisco 4948 can ping out, but no connections inboud

n00b question here I suspect... I received a used Cisco 4948 (not an 'E' or 'F') Switch that I am trying to get configured for SSH Management access. I can ping out from the switch to nodes that are ...
0 votes
1 answer
3k views

Cisco ios - loading 15.2 into Catalyst 2960

Is it possible to load cisco ios 15.x into an old 2960 or 3560? I tried to do that (study purpose) and it's throwing an error. The error I see apparently has to do while decompressing the image or at ...
4 votes
1 answer
6k views

Create a internal connection between ISR 4451 and EtherSwitch submodule

In a Cisco ISR 4451 we install a EtherSwitch 48 Port Module. The ISR is working and the EtherSwitch Module too. Now I want to create a route from ISR to EtherSwitch and read some Manuals and Forum ...
2 votes
1 answer
2k views

cisco 3750x switch boot loop after failed IOS software upgrade

I was trying to upgrade WS-C3750X-48T-S IOS software from universalk9-mz.122-53.SE2.bin to c3750e-universalk9-mz.152-4.E6.bin First I deleted all files under flash: folder, then downloaded new one ...
2 votes
1 answer
613 views

How to upgrade or flash IOS on Cisco 4503E without flash?

I am trying to restore Cisco catalyst 4503E switch. When I turn on it I enter rommon mode? How to restore or fix this problem ? Unfortunately, I haven't a flash card. Here is my screeenshots:
6 votes
3 answers
4k views

OSPF default route, 2 routers connecting to ISP

At work, we have a network with 2 routers connected to ISPs, and other routers in our internal network like this: ISP ISP |(BGP) |(BGP) R1 ...

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