Questions tagged [cisco-ios]
For discussion about Cisco's Internetwork Operating System - Cisco IOS
557
questions
0
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17
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how to limit or block broadcast traffic on ASR920 service instance EVC
I don't want to turn off all port,
I want to block completly broadcast traffic,
or the best to limit rate to 500 pps broadcast, all more to drop.
Is there any way to do it on Cisco ASR920?
I have ...
- 21
2
votes
0
answers
55
views
Cisco Access Switches: Monitoring AAA server dead via SNMP?
This is a new setup of Cisco access switches (2960S, 2960X IOS with 15.2(2)E9, but mostly C1000 with IOS 15.2(7)E*), with a Cisco ISE 3.0 as authentication server for 802.1X, config style is to be ...
- 7,696
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votes
1
answer
54
views
BGP Protocol configuration between two VPC
I would need to configure a cross connect between two VPC networks via SFP Fiber. Unfortunately I'm new on BGP configuration and would need confirmation that I'm doing it on the right way...
I have ...
- 103
0
votes
1
answer
140
views
Cisco ASR 1001 transceivers not working
I've a Cisco ASR 1001 v03.
When it got to my hands it wouldn't save the config after reboots, after some research I found out the config-register had a wrong value and it was fixed by running ...
- 123
3
votes
1
answer
41
views
Cisco 9400-Supervisor Engine 1XL uplink help
I have inherited a Cisco 9400 with 6 line cards installed. I am trying to use some ports on one of the cards. I noticed that there is no link activity lights, no indication of any activity.
I think ...
- 95
1
vote
1
answer
29
views
Cisco 4500X TCAM question on PBR
I have a pair of 4500x in VSS mode and i have 100-150x SVIs and i have PBR under those SVIs and i am changing their next-hop, i want to know PBR and changing next-hop happens in TCAM, hardware or it ...
- 511
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votes
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answers
30
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No Adjacency-SID label in packets in SR topology
I configured Segment-Routing on Cisco IOS XE 17.03.3 in lab environment. You can see topology in the attachment. I configured IS-IS as IGP protocol. It also advertise SR labels. Global-SID static ...
- 1
0
votes
1
answer
37
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Cisco ACL Entries
I have a cisco 4500x and n5k-5672up and in their datasheet mentioned that we can have "Security ACL Entries (1K=1024) 128K (64K ingress and 64K in egress) Shared with QoS" for 4500x and &...
- 511
1
vote
0
answers
33
views
TACACS Through ASA L2L Tunnel
Hello see below network diagram.
I am trying to configure the Branch Router (10.1.1.1) to use TACACS AAA on the HQ-AAA-Server host (192.168.10.10). TACACS works fine for the Branch-FW1 ASA device ...
- 121
2
votes
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answers
43
views
Problem with bgp aggregate-address behavior in iOS when a large number of OSPF routes update all at once
We have a direct connect setup to AWS using BGP. We are running a ISR4451 with IOS XE 16.03.06.
I have a strange situation where the AWS BGP neighbor drops our connection with the notification: ...
- 121
2
votes
1
answer
108
views
AAA Authorization on IOS
Still working away on a project (not for real life deployment so don't worry about seeing passwords).
I have a Tacacs server set up for centralised AAA. I am trying to set up two users, "admin&...
- 121
1
vote
2
answers
51
views
events log in cisco
Is there log file just like events file in windows showing what happened,who did what, kind of ? I could not see with show archive log.some switch goes down and support guys plug off/on cisco switch, ...
- 125
1
vote
0
answers
40
views
Route-map to manipulate metric in EIGRP
I have following Setup
R1 --- R2 --- R3 --- R4 --- R5
The same network is being advertised from R1 and R5. There is some difference in delay between the two paths R1-R2 and R4-R5. So the route from R1 ...
- 1,635
4
votes
3
answers
217
views
IOS Memory allocation error after ping
I have written a script in Tera Term for a Cisco IR809g which pings 3 different routers(IR 809g) in 2 different networks over the cellular interface. After +- 6 hours I'm getting a Memory allocation ...
- 61
0
votes
0
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35
views
Update IOS on Cisco CGS2520 Switch
I need to update the IOS on a Cisco CGS2520 Switch. Not stacked, single switch
I have never done this before and I have a couple questions.
I do not have physical access to the switch.
Looking at the ...
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answers
40
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How do I load VLAN database between switches (CISCO 2960)?
I glad for any help on this topic
--
netanel
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2
answers
62
views
Client's ARP requests affect whether Cisco C897VA receives packages or not
So I have bought used ISR C897VA with an issue: when vlan1 is pinged from windows there are quite a lot of "Request timed out"s.
Config-register 0x2142 has been done, as well as resetting ...
- 103
0
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0
answers
175
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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
- 1
0
votes
1
answer
171
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 - ...
- 35
0
votes
1
answer
62
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?
- 103
1
vote
1
answer
58
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 ...
- 35
0
votes
0
answers
44
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.
- 1
0
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0
answers
56
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 ...
- 1,635
0
votes
0
answers
192
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/...
- 35
0
votes
1
answer
39
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 ...
- 35
2
votes
2
answers
111
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 ...
- 35
0
votes
1
answer
38
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 ...
- 389
0
votes
1
answer
61
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 ...
- 3
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votes
1
answer
53
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 ...
- 103
0
votes
1
answer
166
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
1
answer
246
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 ...
- 133
0
votes
1
answer
412
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 ...
- 511
0
votes
1
answer
185
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 ...
- 327
0
votes
1
answer
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 ...
- 25
4
votes
3
answers
5k
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
!
...
- 209
1
vote
1
answer
469
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 ...
- 516
0
votes
1
answer
181
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 ...
- 1
2
votes
2
answers
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
2
answers
880
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 ...
- 671
2
votes
1
answer
45
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,...
- 209
0
votes
1
answer
59
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
...
- 157
0
votes
2
answers
103
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 ...
- 25
0
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0
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408
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
2
votes
1
answer
201
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 ...
- 1,635
2
votes
1
answer
69
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 ...
- 516
1
vote
2
answers
88
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 ...
- 131
1
vote
1
answer
1k
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-...
- 484
0
votes
2
answers
83
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 ...
- 103
1
vote
1
answer
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 ...
- 11
0
votes
1
answer
129
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 ...
- 103