Cisco on Blog - uTIcARdI

IOS command:IP classless

Sat, 09 Feb 2019 00:00:00 +0000

I wrote down this article in 2009-03-13 when I was looking for my first job. Taking this again today as preparation for CCNP.

Topology:

Topology

Configuration

Configured IP addresses on the routers
Note: The subnets of R1’s Loopback1 and R2’s Loopback1 belong to the class A address.
Execute command “ip classless” on both R1 and R2 (The command has been the default since IOS 11.3)

Run ASA9.1 on EVE(UNL)

Fri, 21 Dec 2018 00:00:00 +0000

This blog discusses ASA, not ASAv. Refer to

It’s possible to run ASA9.1 on EVE-NG (UNL, unified network lab), so I did a try:

Image preparation

No, I can’t provide the image to anyone, and I won’t respond to any question about it. Please Refer to following posts for the image file:
Refer to http://www.eve-ng.net/index.php/documentation/images-table, EVE only support hda.qcow2 format disk. Covert your image to qcow2 format before the next step.

Ansible-Access Network via Netconf

Thu, 11 Oct 2018 00:00:00 +0000

Continue to try ansible with the device which was configure in netconf feature on Cisco IOS/IOSXE.

Ansible Inventory:

---
netconf:
hosts:
 netconfIos:
 ansible_host: "172.16.254.100"
 ansible_network_os: "ios"
 ansible_ssh_port: 22
 netconfJunos:
 ansible_host: "172.16.254.9"
 ansible_network_os: "junos"
 ansible_ssh_port: 830
vars:
 ansible_connection: "netconf"
 ansible_ssh_user: test
 ansible_ssh_pass: test123

Note:

ansible_connnection should be ‘netconf’
Be careful on the netconf port, it should be 22 if you enable netconf over SSH (the default port is 830)

PlayBook:

- name: IOS
hosts: netconfIos
gather_facts: false
tasks:
 - name: Get config for IOS devices
 netconf_get:
 source: running
 register: iosnetconf

 - name: Display output
 debug:
 msg: "{{ iosnetconf.stdout }}"

Note:

Netconf feature on Cisco IOS/IOSXE

Sun, 07 Oct 2018 00:00:00 +0000

I tried to see how Ansible works with the netconf feature on Cisco and Juniper in past days: Juniper’s official document is clear and easy to follow. but for Cisco, I followed NETCONF over SSHv2, unfortunately, I was stuck on it for 6 days.

OS Version

Cisco IOS XE Software, Version 16.04.01
Cisco IOS Software, Linux Software (I86BI_LINUXL2-IPBASEK9-M), Experimental Version 15.2(20170809:194209) [dstivers-aug9_]

NetConf Requests

Tried many requests, all failed:

The hello (works) request:

Ansible-Access Network via SSH

Tue, 04 Sep 2018 00:00:00 +0000

After Telnet, continue to discuss how to access network device via SSH with Ansible.

For SSH access, we should consider 3 methods:

Username/password
Username/Public-Key without password
Username/Public-Key with password

Same EVE lab as the Telnet one: The Cisco IOS Router-192.168.1.99 is for SSH

Topo

Enable SSH on the router

Jump #1 username/password part to public key configuration, I discussed how to configure public key on IOS router with Putty before, instead of windows/putty, openssh is useful for generating keys on MAC OS.

Ansible-Access Network via Telnet

Tue, 04 Sep 2018 00:00:00 +0000

I’m learning Ansible by reading the official document and some books like Ansible入门. Most of the instructions show you how to deploy or maintain the services on Linux, or file operations. But what I do is trying to explore its capability on network device management automation.

The most important thing to practice routers/switches/routing protocol is accessing the device and configure it via CLI when I started to learn network, so I start my ansible tour by accessing the network device from CLI too.

Cisco IPS–Inline VLAN Pair mode

Fri, 24 Mar 2017 00:00:00 +0000

Setup Cisco IPS on EVE

I failed to setup Cisco IPS on EVE(ver 2.0.3-53). I Downloaded Cisco IPS ova file via certcollection (mega)

Followed the [instructions](http://certcollection.org/forum/topic/266792-emulating-ips-on-unl/ http://www.cznetlab.cz/index.php?cat=cciesec&subcat=unlips) for IPS Interfaces.

and met the issue:

Cisco IPS failed to ping anything out of it, I run traffic capture on IPS’s interface, no packet out when I execute the ping command.

Related post on EVE official forum, and the official answer is: This image is corrupted and not working neither on UNL nor EVE

Run NX-OSv 9000 on EVE(UNL)

Sun, 08 Jan 2017 00:00:00 +0000

Refer to how to add NX-OXv 9000 to GNS3

1. Download image files

Here is the NX-OSv9k image file from Cisco (nxosv-final.7.0.3.I5.1.qcow2). Please note that you must have a service contract with Cisco in order to download it.

No I can’t provide the image to anyone.

2. Copy image to eve(UNL)

change file name to ‘hda.qcow2’

copy source file to ‘/opt/unetlab/addons/qemu/nxosv9k-7.0.3.I5.1’

run

/opt/unetlab/wrappers/unl_wrapper -a fixpermissions

3. Add a New node for nxosv9k

Copy the php file to ‘/opt/unetlab/html/templates/’

Trouble shooting: Cisco router DHCP No option 125

Wed, 13 Nov 2013 00:00:00 +0000

Topology:

Topo

Configure DHCP on Cisco router 2811 to assign a static IP to the italkBB: Cisco SPA 1202.

start DHCP service by command:
```
service dhcp
```

debug on Cisco router to check DHCP request by the commands:

debug ip dhcp server packet
terminal monitor

Debug info :

DHCPD: DHCPREQUEST received from client 0100.1c23.3541.98

configure DHCP

Configuring SSH public key authentication on Cisco IOS Device

Fri, 08 Nov 2013 00:00:00 +0000

SSH public Key types:

RSA key use with SSH1 and SSH2 protocol
DSA key use with SSH2 protocol

Note: DSA is weak than RSA

The Key pairs:

Public key: SSH.com使用的RFC 4716指定的公钥格式，而OpenSSH使用了另外的格式
Private Key: SSH v1私钥只有一种标准格式，但SSH v2私钥格式很多，OpenSSH、ssh.com、puty、winscp格式不同且不兼容

Generate the Key

SecureCRT

SecureCRT-PublicKey-1

SecureCRT-PublicKey-2

SecureCRT-PublicKey-3

密钥类型有两种: DSA、RSA. Secure CRT提示多种服务器不支持RSA, Cisco IOS supports RSA only.

SecureCRT-PublicKey-4

通行短语为对私钥加密的密码，注释为提示输入密码时的提示，两项均为可为空

SecureCRT-PublicKey-5

SecureCRT-PublicKey-6

SecureCRT-PublicKey-7

为了更好的兼容性和适用性，OpenSSH format is prefered，Choose the location to save the key files：

SecureCRT-PublicKey-8

点击’Finish’后会弹出对话框：

SecureCRT-PublicKey-9

如果选择’Yes’,会影响’快速连接’中的公钥指向保存的文件:

SecureCRT-PublicKey-10