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

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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 ...
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20 views

Cisco 801 - Authentication failed for client (Unknown MAC) on Interface Fa0 [on hold]

I have a little big problem here: I received a Cisco 801 last month. I wanted to set up a static IP in one interface. So, I connected to the router console an found a login prompt. Given that I ...
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1answer
33 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?
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1answer
22 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?
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1answer
44 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 ...
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1answer
65 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
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1answer
161 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?
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1answer
29 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 ...
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2answers
603 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 ...
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0answers
103 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
15 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 ...
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1answer
78 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 ...
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2answers
80 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 ...
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2answers
119 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
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0answers
130 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 ...
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0answers
19 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
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1answer
67 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 ...
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0answers
49 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
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1answer
387 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 ...
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0answers
51 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
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3answers
491 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 ...
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2answers
167 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
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2answers
282 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
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1answer
238 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
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2answers
61 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 ...
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3answers
109 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
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1answer
34 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
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1answer
116 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
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1answer
59 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 ...
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0answers
50 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
769 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 ...
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1answer
34 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?
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1answer
83 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 ...
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2answers
60 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....
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2answers
193 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
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1answer
34 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 ...
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1answer
61 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 ...
2
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1answer
327 views

Can't use “dot1x” command in Cisco Packet Tracer

I am trying to configure 802.1X authentication on a Cisco switch 2960 in Cisco Packet Tracer software. Here I found the offical guide: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/...
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2answers
548 views

Changing The Stack Master of a Catalyst 3750 Without Losing Connection

Currently I have 5 Catalyst 3750 V2-48TS as slaves and 1 Catalyst 3750g 24TS-1U as the Stack Master. I was wondering if there was any way to change the Stack master to one of the slaves without ...
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1answer
112 views

Excessive “Failed to read module serial eeprom” on Catalyst 4507

I have a plethora of these messages %C4K_CHASSIS-3-LINECARDSEEPROMREADFAILED: Failed to read module 5's serial eeprom, try reinserting module on my Cisco Catalyst 4507R. Thing is, there's nothing ...
3
votes
2answers
310 views

No passive-interface error

I'm trying to nest some EIGRP configurations on a router in GNS3. I'm trying to connect the EIGRP 2801 in SW01 to RTR-01 and EIGRP 2864 to RTR-02 when I do. When I put no passive-interface ...
3
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1answer
61 views

How to permit behaviour in Cisco access-list commands?

If a host on a network is permitted to access another host on a different network via an ACL on the source host's router, does that automatically deny other hosts on the same network as the source ...
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1answer
741 views

Create a internal connection between ISR 4451 and EtherSwitch submodule

In a Cisco ISR 4451 we install a EtherSwitch 48 Port Module. The ISR is working and the EtherSwitch Module too. Now I want to create a route from ISR to EtherSwitch and read some Manuals and Forum ...
4
votes
1answer
893 views

When and where to use Spanning-Tree (Portfast)

The tl;dr, in which scenario (switch-to-host, or switch-to-switch) do I use spanning-tree portfast or spanning-tree ...? We had a catastrophic network outage today. My first question to my boss was "...
8
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1answer
199 views

Cisco IOS Tcl - Overhead

I've not been able to find much in regards to TCL other than the Cisco PDF "Cisco IOS Scripting with TCL Configuration Guide" and I just have a few queries. I'm looking into potentially utilising ...
2
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1answer
176 views

Cisco 871 router vlan configuration and Routing between interfaces

I'm planning to enable the connectivity with our access points as shown in the Diagram. I would like to understand how can I enable the routing between 192.168.1.1/25 (FE4)and 10.140.134.0/25(FE1). ...
2
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1answer
334 views

How to configure site to site VPN between Cisco ASA and Cisco router? [closed]

I have CISCO ASA on one site and CISCO ROUTER on other side, both have outside interface facing public IP and doing NAT for internal VLAN's. How to connect different VLAN's on one site to VLAN's on ...
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1answer
42 views

Why is my Cisco MMS891 assigning IP addresses with static NAT entries to devices via DHCP?

I have a Cisco MMS891 ISR as my edge router with several static NAT entries, which are set up to NAT my LAN IP addresses (which are statically assigned to printers) to access an externally hosted ...
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0answers
24 views

WCCP filtering with L7 content inspection

I currently have a working WCCP setup which uses the basic service declaration (like ip wccp web-cache ...). My concern there is that this is limited to the ports that the proxy will advertize: if ...
1
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1answer
337 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 ...