Questions tagged [cisco-ios]
For discussion about Cisco's Internetwork Operating System - Cisco IOS
532
questions
0
votes
1answer
29 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
13 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
280 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
!
...
0
votes
1answer
12 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
32 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
1k 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
431 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
31 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
0answers
10 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
33 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
32 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
31 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 ...
1
vote
1answer
48 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
1answer
32 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 ...
0
votes
0answers
17 views
NAT syntax comparison
Could I know if the NAT syntax on ASA5510 v9.1.7 should be the same on ASA5512 v9.9 or v9.12.3 ?
Hope to get your answer.
Many thanks
1
vote
1answer
186 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
51 views
Why we define pool for declaring CISCO router DHCP?
In case declaring DHCP server in CISCO routers, should define pool with network addresses.ā
Example
Router(config)#ip dhcp pool net1
Router(dhcp-config)#network 192.168.1.0 255.255.255.0
The router ...
1
vote
1answer
41 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. Iād like to connect these up to each other and form ...
0
votes
1answer
28 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
39 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
2answers
31 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
54 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
18 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 ...
2
votes
1answer
57 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
56 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 ...
0
votes
1answer
62 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
45 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
46 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
46 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
154 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
20 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
Ā switchport trunk allowed vlan none
Ā switchport mode trunk
Ā mtu 9192
Ā ...
1
vote
0answers
18 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
18 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
160 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
97 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 ...
0
votes
1answer
84 views
Issue w/ Cisco router and failed NAT and static default route
I have a cisco router that is using a VRF to support a site to site VPN tunnel. I have added a second network to the router for non-VPN standard internet use. My problem is that my default static ...
1
vote
1answer
327 views
Lubuntu 18.04 can't SSH to Cisco Router: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1 [closed]
I'm not sure if this problem caused by Lubuntu or Cisco Router side.
Lubuntu = 192.168.1.100
Cisco Router = 192.168.1.1
Ubuntu 18.04.4 LTS
user@linux:~$ lsb_release -a
No LSB modules are available.
...
0
votes
1answer
69 views
Firmware of Cisco Phone
i want to configure IP phone Cisco DX650 with Sip.Anyone have idea about it how i can upload firmware of sip feature
0
votes
0answers
19 views
Cisco IE2000 - NTP Doesn't Associate
I'm having a very weird issue with a switch. It doesn't want to associate to my NTP servers.
My config is very simple:
ntp server ntp1.domain.com
ntp server ntp2.domain.com
ntp server ntp3.domain....
0
votes
0answers
15 views
What's the difference between “IP NAT Inside Source” and “IP NAT Inside Destination” commands in Cisco routers? [duplicate]
As much as i know both of this commands translate source address of packets that travel from inside to outside and destination address of packets that travel from outside to inside,so what's the ...
2
votes
1answer
453 views
Link Aggregation from Cisco to Palo Alto using 10 gig interfaces, port on Cisco shows “waiting to be aggregated”
I am trying to bundle two 10-Gig interfaces on PA-3020 to Cisco Cat9300. Previously, I had bundled two Gigabit interfaces on same devices and everything worked fine. But now, when I try to configure ...
2
votes
1answer
38 views
Cisco snmp-server single user for multiple snmp versions
Attempting to maintain SNMP v2c compatibility while implementing SNMP v3 on cisco switch 5506cx.
Would a user that was previously used for v2c see issues with v2c if it is added to a v3 group?
For ...
2
votes
1answer
71 views
Prevent static NAT to respond to ARP requests
We are trying to merge 2 networks with overlapping IP spaces: This is the configuraiton so far:
interface Tunnel1
description VPN Port CompanyA
ip vrf forwarding LAN
ip address 172.18.0.79 255.255....
2
votes
0answers
635 views
Cisco AIR-AP1852i-E-K9 stuck in “waiting for uplink[…]” after startup
I pulled an old cisco AP from a shelf today at work to test something, and after starting up and connecting with PUTTy, i was greeted with (after startup), this - repeating over and over:
[*02/16/...
0
votes
0answers
29 views
Cisco PPTP server available routes protocol
I have a 2921 Cisco router in one place, and a Windows XP computer on another.
I made my Cisco router as PPTP server, and my XP computer as a client.
The router is located within a LAN with address ...
0
votes
0answers
47 views
Cisco C3750 and PRTG netfllow
I have a core switch (backbone) of our network that broadcasts all the vlans to other switches. I am trying to configure netflow on the switch and link it up to a Netflow sensor on PRTG.
I followed ...
1
vote
1answer
175 views
What is the difference between trustpool and trustpoint on Cisco IOS?
On Cisco IOS, there is trustpool and there is trustpoint. I have seen imported certificates in either of the two. And it seems SSL connection works when either location has the certificate it needs. ...
1
vote
2answers
63 views
Cisco Switch without VLAN support?
I've been reading about VLAN and wondering is there any Cisco Switches that do not support VLAN?
So far, all switches that I found do support VLAN. This is one of the example in my lab.
Cisco-Switch-...
0
votes
0answers
58 views
Cisco Guestshell - Bridging of VirtualPortGroup0
i'm fiddling around with ne virtual-services functions of IOS-XE.
Is there a possibility to bring interface "VirtualPortGroup0" into a bridge domain with some physical interface of the router?
It's ...
0
votes
2answers
47 views
Why doesn't kernel itself had entire L2/L3 protocol stack? [closed]
I know kernel itself handles protocols in layer 2, layer3 and layer 4 at ipv4 stack, but why can't kernel itself doesn't have protocols such as STP/RSTP/xSTP/OSPF...etc, implemented.
Why should we ...
