Questions tagged [cisco-ios]
For discussion about Cisco's Internetwork Operating System - Cisco IOS
542
questions
0
votes
0answers
29 views
No Voice commands on cisco router
I cannot find voice commands on my router,
I have licenced it but no voice commands or sip are found
Its on packet tracer.
Cisco router 2911
Thank you
0
votes
1answer
32 views
Addresses in router's subinterfaces overlapping [duplicate]
I can't really understand why I'm getting overlapping addresses in subnets when they're between the allowed range.
I have the network 192.168.1.0/24, and I have to create 3 subnets:
A - 58 Hosts
B - ...
0
votes
1answer
58 views
How to query which line I am configuring in a Cisco router?
The Cisco router prompt shows only that I am configuring a line: config-line.
How can I make IOS to print exactly which line I am configuring?
1
vote
1answer
29 views
ARP sending an ARP request on changing port IP address
Using the c7200 images on GNS3. I configured two routers as so:
With arp debugging on, after assigning an ip address I see that each router sends a gratuitous ARP response packet (only debug output ...
0
votes
0answers
23 views
Cisco firewall Firepower 1120 how to access global configuration mode?
Cisco firewall Firepower 1120 how to access global configuration mode?
Commands enable and configure terminal are not working.
0
votes
0answers
31 views
Cisco DHCP using dynamic updates
I would like to use a configuration on a Cisco router that allows for clients to resolve the names of other clients without the use of mDNS. I have following configuration:
roTST01#show running-config ...
0
votes
0answers
36 views
Can ping from VPC 1 to router and VPC2, but can't ping from switch to VPC2 or router
I have a simple, linear topology in GNS3 that goes like this.
VPC1 > Switch > Router > VPC2
I have the default static IP Routes on the router set to 0.0.0.0 0.0.0.0 Ethernet0/1 and Ethernet1/...
0
votes
1answer
31 views
How to stop automatic entry as privileged exec from console login?
I am configuring my Cisco router and trying to set up access levels.
I was under the impression that level 0 was a very limited mode which almost only allows users to enter the enable command to enter ...
1
vote
2answers
57 views
Unable to add an abbreviated IPv6 to a Cisco router
I am very new to networking and playing around with GNS3. I am trying to configure a router to have 2 IPv6 addresses in a single interface (as far as I understood, this is possible with IPv6)
I ...
0
votes
1answer
20 views
IP Source Guard On Static Networks
I am running a set of Cisco C9300s. I have them configured with ip dhcp snooping, and ip arp inspection with ip dhcp snooping trust and ip arp inspection trust set on the fiber link between the 2 ...
0
votes
1answer
31 views
In France , what language is the Cisco IOS for routers and switches?
If I accept a Network Engineer job in France, what language will the Cisco , Juniper, etc, IOS communicate in?
If it is in French, is there an acceptable workaround that I can install in routers that ...
0
votes
1answer
26 views
Why does a Cisco router advertise a prefix with NDP RA when it has an address in that range?
If I write
interface Vlan1
... {ipv4 config} ...
ipv6 address 2001:DB8:5432:101::/64 eui-64
ipv6 address FDAA:DB8:5432:101::/64 eui-64
ipv6 enable
ipv6 nd prefix 2001:DB8:5432:101::/64
ipv6 nd ...
0
votes
0answers
36 views
show ip nbar port-map is deprecated
If I want to see what parameters NBAR uses to classify traffic into a specific application, i used to use show ip nbar port-map. It was looking something like this:
Router# show ip nbar port-map dhcp
...
0
votes
1answer
88 views
Steps for upgrading to Cisco DNA Center?
Has Anyone upgraded from cisco Prime to Cisco DNAC, if so then Does anyone have Steps (Prep Work) checklist suggestions before beginning the Brownfield Deployment of Cisco DNAC ?
3
votes
1answer
226 views
Cisco ACL numbering
This is a small technical question. I can't seem to find any information on this, so I thought I'd ask here.
I'm currently studying for my CCNA and I'm currently on the topic of ACLs. On IOS standard ...
0
votes
1answer
301 views
4500x ios upgrade
I have a Cisco 4500x-32SFP (with Enterprise License) with cat4500e-universalk9.SPA.03.04.04.SG.151-2.SG4.bin ios and i want to upgrade it to cat4500e-universal.SPA.03.11.03a.E.152-7.E3a.bin which is ...
0
votes
1answer
111 views
Cisco ip helper-address
I am looking at the DHCP documentation and i cannot seam to find how to configure the router to use a loopback interface as the relay-agent. My objective is to use option 82 so that the dhcp server is ...
0
votes
1answer
21 views
Multiple administrator connecting to a router - who has precedence? Can they monitor each other's logs?
Just getting started in Networking. Came across multiple administrators connecting over Telnet.
Does someone who connected first have precedence over everyone else?
Does a admin connected to VTY line ...
4
votes
3answers
2k views
How to remove switchport mode access from Cisco Switch 2960?
This is in Cisco Packet Tracer - this is not a real switch.
Default interface config on Cisco Switch 2960 looks like this
!
interface FastEthernet0/10
!
Then I put it in switchport mode access
!
...
1
vote
1answer
214 views
IP SLA VS tracking IP-route reachability for HSRP
I have two Cisco switches A and B, which I want to use HSRP to track if route to specific IP still works, but according to my understand it could be either IP SLA or tracking IP-Route Reachability ...
0
votes
1answer
99 views
IPCP removing default route when 2 available
I've been stuck on this one in my lab for a while. Any help is appreciated.
Here's my CPE edge topology:
https://i.imgur.com/UZ4u0XG.png
Take the below scenario:
I have 2 circuits coming in that I am ...
2
votes
2answers
2k views
Why does the CISCO's command 'enable secret <password>' produce different hash from MD5?
I am configuring a CISCO's 4331 router password, in Packet Tracer. More specifically I use the command enable secret weakpassword. This command uses by default MD5 to hash the last string (i.e ...
1
vote
2answers
699 views
Safe to remove ip default-gateway?
We recently changed IP schemes from 192.168.x.x to 10.x.x.x In doing so, I noticed that the prior network engineer had ip default-gateway in the configuration pointing to an old default gateway that ...
2
votes
1answer
37 views
Cisco router with 3 spaces between `deny` and `icmp`
I was configuring deny icmp any any traffic when I realized it was not in the config.
I verified it with do sh run | i deny icmp command as follows:
R1#configure terminal
Enter configuration commands,...
0
votes
1answer
30 views
Cisco IOS How to dynamically change the queueing/shaping upload bandwidth for xDSL circuits?
In Cisco 29xx routers with IOS 15.7, we have upload queues (with the classic service-policy output command and the policy-map:
policy-map wan-shaping
class class-default
shape average 1024000
...
0
votes
2answers
56 views
Add allowed vlan to vlan.dat automatically
I have a switch configuration for a Cisco 2960cx that allows a specific VLAN on a trunk but no interface on the switch explicitly accesses that VLAN. So when the configuration is ran for the first ...
0
votes
0answers
230 views
Dual WAN with each ISP in a VRF - Cisco IOS
I have a DMVPN spoke router setup almost identically to the spoke configuration listed here (Also quoted below):
https://www.cisco.com/c/en/us/support/docs/security-vpn/dynamic-multi-point-vpn-dmvpn/...
1
vote
1answer
97 views
SNMPv3 context on IOS-XE does not seem to work with Prime
We recently switched to SNMPV3 and experience the issue, that there is no client data available within prime anymore. So we quickly read about the SNMP context we need to add to our devices ...
2
votes
1answer
53 views
Routing failed after define static route on core switch
Current connection path: 10.40.20.0/24 desktop <-> access switch <-> core switch <-> 10.30.15.33 NAT firewall for internet access
Objective: adding additional path as following to ...
1
vote
2answers
52 views
How can I auto-detect the default WAN gateway on a Cisco router?
I previously connected to my ISP using authenticated PPPoE and provided default routes for IPv4 and IPv6 as follows:
ip route 0.0.0.0 0.0.0.0 Dialer0
ipv6 route ::/0 Dialer0
After switching to a ...
1
vote
1answer
595 views
Force Catalyst 2960X Boot Loader upgrade to the same version
I would like to know if there's a way to force a Boot Loader rewrite on Cisco Catalyst 2960-X switches.
I got one model that runs this release of the Boot Loader: BOOTLDR: C2960X Boot Loader (C2960X-...
0
votes
2answers
64 views
Why we define pool for declaring CISCO router DHCP?
In case declaring DHCP server in CISCO routers, should define pool with network addresses.↓
Example
Router(config)#ip dhcp pool net1
Router(dhcp-config)#network 192.168.1.0 255.255.255.0
The router ...
1
vote
1answer
45 views
Routing between two sites using FTTC Broadband and E-Band Wireless
I have two sites, both with 80/20 FTTC broadband connections that terminate at the standard white box BT modem. The connections both have fixed IP. I’d like to connect these up to each other and form ...
0
votes
1answer
60 views
What is the purpose of Cisco's `ip domain round-robin` feature?
While configuring one of Cisco's routers and reading documentation I've found an interesting feature: ip domain round-robin.
Documentation says, that this options makes dns server rotate entries ...
0
votes
1answer
97 views
How to init connection with a Cisco over serial & minicom?
Trying to connect to a Cisco router, in purpose to learn Cisco skills that could help me finding a job. So, I plugged a cable in the rj45 Console (blue) port of a Cisco 888 router, and other end into ...
0
votes
3answers
52 views
Show ports in use on Catalyst 3570
I picked up a used C3570 and am new to IOS. I am trying to ask the switch to show which ports are in use. My searches lead to the command "show modules" but that's refused by the switch (...
1
vote
1answer
106 views
QoS Policy to not overutilize WAN link
I have a configuration on a Cisco C897VA-K9 router that has a built in DSL modem. It has a simple internet connection via VDSL. There is a VPN configured on the device, that connects back to our main ...
0
votes
1answer
24 views
Traffic flow of tunnel interfaces
I would like to understand traffic flow in a router. In what direction do i need to apply a policy-map in order to affect traffic? Especially regading tunnel interfaces, as traffic both comes and goes ...
3
votes
1answer
455 views
Cisco IOS NTP do not sync time after reboot
I try to setup automatic syncing time on Cisco Catalyst 2960-CG-8TC-L switch using following command.
ntp server 0.cz.pool.ntp.org
and it works and sync time but after switch reload it does not sync ...
3
votes
2answers
92 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 ...
1
vote
1answer
212 views
Cisco DHCP relay with Microsoft DHCP server
Current situation: we have a C3850 switch serving DHCP lease to desktop clients without communicating with any upstream DHCP server
Objective: We would like the C3850 switch continue to serve DHCP ...
0
votes
3answers
125 views
IOS. Whats the difference between these 2 commands
I am completing an online course for the network+ and am going through one of the labs. Here is a diagram of the network in question.
Specifically I have a switch with 24 fast ethernet ports and ...
0
votes
2answers
102 views
When do ACLs on SVIs get applied on Cisco Catalyst devices?
I don't understand exactly when an ACL will get applied when on an SVI. Given the following (pseudo) configuration
int vlan 100
ip address 10.0.0.1 255.255.255.0
ip access-list in in
ip access-...
1
vote
0answers
55 views
Upstream QoS garanteed bandwidth
In the network I'm trying to manage there is a satellite link, the upstream of which is ~ 7 Mbps. In this upstream, I need to allocate 1.5 Mbps of guaranteed bandwidth for one single host, but nothing ...
3
votes
2answers
376 views
How can I use an HTTP CRL on Cisco IOS?
On a Cisco 867 running IOS 15.6(3)M7, I'm trying to do the following:
TEST-GW1(config)#crypto pki trustpoint vpn-p2s-server-11
TEST-GW1(ca-trustpoint)#crl query http://myvpn/crls/21.crl
% URL must ...
0
votes
0answers
38 views
Is it possible to specify a bandwidth parameter per service instance?
I have a physical interface with multiple service instances and policer per service instance:
interface GigabitEthernet0/3
switchport trunk allowed vlan none
switchport mode trunk
mtu 9192
...
1
vote
0answers
94 views
Configue IOS DHCP server to respond to Option 60 class
I have a number of small networks each with about half-a-dozen mostly-fixed hosts. The routers on each network provide DHCP service for the occasional visiting engineer's laptop. I am adding IP ...
0
votes
0answers
22 views
Rate limiting xFTP traffic originating from a Cisco IOS router
We have some routers on marginal cell links that we need to pull files from using TFTP or FTP. During file transfers connections to the router become so slow as to be unusable.
Is there a way to rate-...
0
votes
0answers
391 views
Cisco erase nvram or erase startup-config doesn't work
According to this article, I can delete the current startup configuration files and return the router to its factory default settings with the erase nvram: and reload command.
https://www.oreilly.com/...
0
votes
1answer
194 views
Cisco IOS Sanitization: Any Way to Not Use NVRAM?
We want a method to sanitize Cisco IOS 15 routers (ISR Gen 2) before they are removed from the facility. While a "write erase" works perfectly if the router is breathing, how to sanitize dead routers ...
