Questions tagged [cisco-ios]
For discussion about Cisco's Internetwork Operating System - Cisco IOS
535
questions
0
votes
1answer
8 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 ?
1
vote
3answers
367 views
Cisco IOS - dropping all traffic not translated by NAT
I have a couple of rather basic questions about NAT translation.
For a simple translation like:
ip nat inside source list ACL interface GigabitEthernet 0 overload
If the traffic does not match ACL, ...
1
vote
2answers
50 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 ...
3
votes
1answer
216 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 ...
1
vote
3answers
102 views
Cannot put an IP address on layer two interface
I am trying to assign an IP address to Interface g0/0 on a Cisco 892FSP. However, it keeps telling me that a layer two interface cannot be assigned an IP address. Any ideas?
1
vote
3answers
55 views
Is the static route discover automatically or need run any command in Cisco Router?
Is the static route discover automatically or need run any command?
I have two router, and I have configured the IP address for the link port of them.
but the Router3's route is empty:
Router#show ...
1
vote
3answers
80 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
1answer
186 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
18 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
...
2
votes
2answers
837 views
Allow port 8080 in on Cisco 1841
Having problems configuring an 1841 to allow outside access in mapping some ports to internal addresses.
Need to allow the following:
External IP: port 8080 to 192.168.3.50
External IP: port 8081 to ...
1
vote
3answers
203 views
Routing issue on router
I have created network with 3 routers, 3 switches and 6 computers
Below are configurations,
R1-> serial2/0= 192.168.1.1/30, Fastethernet 0/0= 192.168.1.9/29
R2->serial2/0= 192.168.1.2/30, ...
1
vote
1answer
108 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 ...
0
votes
3answers
43 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 (...
0
votes
1answer
634 views
How to enable RESTCONF server in IOS-XR?
I aim to enable RESTCONF server on Cisco IOS-XRv 9000.
I did not find online anything about enabling HTTP server in this IOS-XR version. However, with NETCONF server can be enabled.
For IOS-XE is ...
1
vote
2answers
483 views
Regarding clns mtu
I understand the below points,please confirm if my understanding is correct.
MTU > MSS
E.g if my MSS is 1460 bytes, then MTU should be at least 1500 bytes(20 bytes for IP header and 20 bytes for TCP ...
8
votes
4answers
54k views
Switchport mode access VLAN & switchport mode trunk on one interface
Googling around to see if this setup on one port is correct (it doesn't look right to me), I'm not really seeing a straightforward answer.
There is an interface with the following configuration:
!
...
1
vote
2answers
353 views
Is it possible to do interVLAN routing on a router on a stick configuration on a Cisco ISR C891F with tagged interfaces?
As the question says,
Is it possible to do interVLAN routing on a router on a stick configuration on a Cisco ISR C891F with tagged interfaces?
Let's I have 2 VLAN.
interface vlan 1
ip address 192....
0
votes
3answers
59 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
55 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-...
8
votes
3answers
997 views
routing between vlans not working
I need to put a Cisco router behind an ISP router.
(The ISP doesn't allow us to use their modem only.)
I've called the ISP technical service and they've set up the connection with me.
Their router ...
1
vote
2answers
1k views
Does service password-encryption encrypt the encrypted enable secret?
On Cisco router:
When enabling enable secret <password> it creates a hash(MD5 I believe) so it cannot be read right of the config file.
And when turning encryption on on all passwords like: ...
2
votes
2answers
92 views
No internet through router
I have the following network setup, but on the computer I can't access anything that's outside of the TP-Link router. When I tried to ping 8.8.8.8, I got reply from 192.168.2.1:Destination Host ...
4
votes
2answers
263 views
PAT not translating at all
I am studying for my CCENT.
I threw together a PAT practice lab.
Other than DHCP and RIP everything is pretty stock.
No VLANs
No security
Just NAT overload on ACCESS router.
I am stumped why it isn'...
0
votes
1answer
65 views
implementing broadcast traffic restriction
Can we restrict the high broadcast traffic from interface in Cisco ASR9k and 7600 routers? If so, what configuration we should apply?
0
votes
1answer
40 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
20 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
434 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
2answers
552 views
Configuring static NAT on Cisco Router
I am trying to configure port forwarding on a Cisco 891F router given by an ISP and directly connected to servers in the 192.168.170.0/24 network. The ISP recommended using the ip nat inside source ...
1
vote
1answer
34 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 ...
1
vote
1answer
45 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 ...
0
votes
1answer
48 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
477 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
2answers
34 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
58 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/...
2
votes
1answer
52 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
44 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
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
286 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
1answer
48 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
53 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 ...
0
votes
1answer
33 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 ...
7
votes
1answer
901 views
How to break apart an IPv6 /56 6rd delegated prefix from ISP into multiple /64 VLANs for use with SLAAC EUI-64? [Cisco]
I have CenturyLink Internet service, and they have a 6RD IPv6 deployment where they hand out an IPv6 delegated prefix /56 block to me and allow me to use it as I wish. My Cisco ISR router receives the ...
1
vote
1answer
70 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 ...
4
votes
3answers
28k views
Meaning of the ip default-gateway L2 switch
What is meaning of the ip default-gateway command on a Cisco L2 switch? I read something about it on the Internet, but there was written that it allows you to Telnet to the switch. I am little bit ...
0
votes
1answer
22 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
140 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
61 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 ...
4
votes
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 ...
