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Use this tag for discussion about Cisco's Internetwork Operating System - Cisco IOS

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0answers
27 views

why does CISCO IOS devices has 16 VTY lines? [on hold]

The newest CISCO IOS devices has 16 VTY lines. why does they make 16 vty line ?. i mean whats the point on having 16 vty line on devices that are controlled only by administrator.(only 5 enough).
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1answer
29 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 ...
0
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1answer
47 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 ...
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2answers
47 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?
3
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1answer
39 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?
1
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1answer
47 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-...
1
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1answer
37 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....
3
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1answer
45 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 ...
1
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0answers
25 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....
0
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1answer
47 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 ...
4
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1answer
44 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 ...
0
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1answer
75 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 ...
0
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1answer
51 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 ...
2
votes
1answer
100 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 ...
0
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0answers
56 views

Configuring Cisco IR809-G LTE router config help

sorry in advanced for the long post this has been racking my brain for 4 days I am extremely new to cisco and need to configure an IR809-G router with a failover script to that if one sim fails it ...
0
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1answer
35 views

Subinterfaces at Cisco routers

What is behavior of subinterface on cisco router that has configured #encapsulation dot1q vlan_id but has no IP address configured? Will it work as L2 interface? Or will not work at all?
0
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1answer
27 views

Can cisco router interfaces be configured to be L2 interfaces?

Can cisco router interfaces be configured to be L2 interfaces? Like #no switchport command turns L2 port to L3 port at cisco switches?
0
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1answer
66 views

Factory Reset Cisco 3560: Stuck in loop

I recently acquired a used Cisco Catalyst 3560 and I am trying to factory reset it. When I enter the recovery process (by holding MODE), I get stuck in this loop at the "switch: " prompt. How do I ...
2
votes
1answer
91 views

Fix our Cisco switch overwhelmed by console logging

I have a setup with dual redundant Cisco catalyst 4506-E using the WS-X45-SUP8L-E supervisor engine and two 48-port switches below it. My task is to access and modify the switch configuration. ...
4
votes
1answer
172 views

Filtering IP packets that contain IP options using ACL

Is it smart to have ACE #deny ip any any option any-options enabled as part of hardening the router? Is there some legitimate traffic that use IP options? Or should I use selective drop?
1
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1answer
34 views

Help with this acl

This is what i am trying to do Deny the network that host 200.200.200.10 is on, telnet access to R3 Permit host 200.200.200.10 to telnet to R3 Deny host 200.200.200.10 all access to host 204.10 on ...
8
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2answers
639 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 ...
3
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0answers
133 views

Hardening Cisco router on Internet-MANAGEMENT PLANE

I need confirmation that I understood the Cisco manual right. So my network is like this: ISP_RTR ---x.x.x.x/30--- Perimeter/Edge_RTR ---y.y.y.y/30--- FW1 --- DMZ1 ...
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0answers
17 views

IPsec VPN Setup

Below is the flow 10.1.0.0>Data Center Firewall>Internet Router> ----Internet---- So basically i am setting up new ipsec tunnel between two Cisco internet routers for branch office users to access ...
1
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1answer
83 views

Using a Cisco router to create a network inside an existing one

I have to make the 192.168.1.* network inside the already existing 192.168.0.* network using a Cisco 2821 router. I'm not familiar with Cisco IOS, and I have no idea what commands to use and how to ...
4
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2answers
92 views

Automation out of the box?

Can anyone point me in the right direction ? I have been recently learning python with the goal of learning more about network automation, I can copy, paste, tweak and adjust a simple script to ...
5
votes
2answers
149 views

QoS shaper, shapes traffic without dropping packets?

I have a problem with my QoS policy, or I should better say, I have a problem understanding how my policy manages to achieve what ask of it without dropping a packet! Here is the scenario: We have ...
5
votes
0answers
194 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 ...
0
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0answers
20 views

Certificate Path Validation in PKI

I've been trying to learn PKI and making various scenarios to understand the concepts properly. I considered a scenario with multiple sub CA and one trusted root CA. So, one thing that i can't figure ...
2
votes
1answer
75 views

DHCP Relay Problem

I'm trying to get DHCP to work between these two Devices. Any tip's would be wonderful! Switch Config Switch#show run Building configuration... Current configuration : 1596 bytes ! ! Last ...
0
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0answers
81 views

show vlan usage on cisco port configured with voice vlan

When a port is configured on a cisco switch for both data and voice, how does one show whether the connected device is using the voice or data vlan. interface GigabitEthernet2/0/8 switchport access ...
3
votes
1answer
534 views

How to Disable telnet on Cisco switch totaly?

I have disabled telnet on Cisco 2960G switch by putting: line vty 04 transport input ssh but now when I try telnet to the switch I get message saying,password required but not set I am wondering ...
1
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0answers
71 views

Amazon AWS VPN Bidirectional Device Access

After setting up an Amazon VPN connection and configuring my gateway using the downloaded configuration, I am able to directly ssh to the private IP of an EC2 instance in my VPC. However, both the EC2 ...
4
votes
3answers
627 views

Configuring OSPF on two directly connected routers which are in different areas

I want to configure OSPF on the topology below. The problem is when I connect two routers to each other and when I config one router to area 0 and another one to area 1, they don't see each other as ...
0
votes
2answers
273 views

IPSec VTI on Cisco ISR reporting up/up and decapsulating packets, but not encapsulating

I'm configuring a VPN connection between two sites. Site A has an ASA (9.8.2) and the other site an ISR 2911 (15.4 I think - I'll have to double check). I'm using VTIs for a routed VPN. The tunnel is ...
3
votes
2answers
507 views

Editing startup-config

I have a Cisco router, and I want to remove a few lines from startup-config. How could I do it? Do I need to copy it over to a PC, edit it there, then copy it back, or can I do it through the serial ...
3
votes
1answer
255 views

CSCvg76186 - Cisco Smart Install Remote Code Execution and Denial of Service Vulnerability

If you missed this Catastrophic severity 1 vulnerability, check the temporary solution below, if you do not want to upgrade your software to a not properly tested software. There are currently, at the ...
2
votes
2answers
76 views

Converting a Cisco 827 for FTTN NBN

I have a customer who is moving to NBN in a few months and I thought I would start to look at the config changes now when there is no time pressure. I assume I will have 2 options: Change the ...
1
vote
3answers
171 views

Translate between multicast addresses

I have an application with a bug that does not recognize a certain multicast address as valid. It's an address used by another system i don't have control over, and these two systems communicate via ...
3
votes
1answer
41 views

Config logging on which cisco IOS?

I want to configure configuration logging on network devices by running following commands. archive log config logging enable I want to know which Cisco IOS and device support it? I used cisco ...
2
votes
1answer
171 views

Unable to enable “Directed broadcast” on router in packet tracer?

I have a topology like below, wherein 2 subnets with address 192.168.0.0/24 and 192.168.1.0/24 are connected to a single router, Router0. Now i want to send a directed broadcast from PC0 on subnet ...
2
votes
1answer
62 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 ...
0
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0answers
58 views

Allow traffic from only IP address on Cisco router to perform NMAP scan

I need to quickly run an NMAP scan against ISR4K router, and I would like to be able to disable all traffic to it, except from one IP address, where the scan is done. Then secondly, what configs do I ...
3
votes
1answer
1k 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 ...
1
vote
1answer
43 views

Extended ACL not working with “host”-Attribute in Cisco Packet Tracer

Here's the output (or the commands) which fails: Normally it should work! What's wrong here?
1
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1answer
106 views

IPv6 ACL in Packet Tracer - why doesn't it work?

I typed in this command: ipv6 access-list NO-SERVER-ACCESS permit ipv6 2001:db8:18::/48 host 2001:db8:18:6600::0010 eq 80 permit ipv6 2001:db8:18::/48 host 2001:db8:18:6600::0010 eq 443 permit ...
1
vote
2answers
76 views

Cisco IPSEC Tunnel with hidden local networks

I've got an ipsec tunnel that's up and working with ATT. They require that the phase 2 IP's not be local LAN's, but public IP's. So, my phase 1 is X.X.X.132, and my Phase 2 is on the same subnet as X....
0
votes
2answers
273 views

Stateful DHCPv6 Default Router

I understand that stateful DHCPv6 cannot provide hosts with a default router, as DHCPv4 could. Hosts would need to determine the default router based off of the information in RA packets. In my lab, ...
1
vote
1answer
38 views

Where did `private_sg-0` come from?

I'm configuring my first Cisco product (WS-C3560CX-12TC-S) and trying to get to grips with aaa. I'm used to *nix where the first thing you do with headless devices is enable and configure SSH access ...
1
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1answer
65 views

IP SLA with follow on actions

Good day, I have an odd one here. I am wanting to run an IP SLA to ping another device in the network, and if it stops responding, or the interface goes into a down state. I would like it to run a ...