Cisco networking products: cisco routers

2015年2月10日星期二

Booting Router from a Local TFTP server

When working with Cisco routers, many-a-times we wish to boot the router from a local TFTP server. Here is a brief description of how the router can be configured to boot from a TFTP server.

Step 1: Setting up required variables in ROMMON

Whenever a Cisco router boots up, it initially goes into the ROMMON mode and then boots up into the IOS from there. Now, inorder to boot up into the IOS, it obviously needs access to the IOS from ROMMON. So, inorder to boot from the TFTP server, we first need to ensure that the router has access to the TFTP server from ROMMON mode, from where it can download the IOS each time that the router needs to boot up.

There are some variables which we need to set in ROMMON mode, which will ensure that the IOS gets downloaded from TFTP.

So, here are the sequence of events that we need to carry out to set these variables.

Power cycle the router, and during bootup, press ctrl + break continuously so that the router goes into ROMMON mode.
Once in ROMMON, give the following commands:

rommon 1 > IP_ADDRESS=<ip address of router interface>

rommon 2> IP_SUBNET_MASK=<subnet mask for the above IP>

rommon 3 > DEFAULT_GATEWAY=<default gateway for router (can be same as TFTP server IP)>

rommon 4 > TFTP_SERVER=<IP address of TFTP server>

rommon 5 > TFTP_FILE=<name of IOS to be used for bootup (including the .bin extension)>

rommon 6> tftpdnld –r

(the ‘-r’ parameter ensures that when the IOS is downloaded, it is not stored in flash, but is directly decompressed into the DRAM during router bootup. So the flash is completely bypassed here.)

Once the above commands are entered, the router will start downloading the IOS from the TFTP server. After the download is complete, the router will reload automatically, and boot up into the IOS that was specified above.

The ‘show version’ output will have the following statement:

System image file is "tftp://<IP of tftp server>/<IOS image name>"

This step ensured that we have the correct variables set up in ROMMON for the router to reach the TFTP server and download the IOS from there on subsequent boot-ups.

Step 2: Changing boot variable in the IOS

Now that the router has booted successfully into the IOS and all the required variables have been set up in ROMMON, all that is left to do is to set the boot variable to point to the TFTP server in the IOS, so that the router looks for the TFTP server during bootup to find the IOS image.

This can be configured by the following command in global configuration mode:

Router(config)# boot system tftp <IOS image name> <IP of TFTP server>

Save the configurations.

We have now setup all the desired variables (in ROMMON and in the IOS) to ensure that the next time that the router boots up, it will download the IOS from the TFTP server, decompress it and then boot into the IOS.

Please note that since the IOS has to be downloaded from the TFTP server each time that the router boots up, the boot up process takes a bit of time.

It refers from:

https://supportforums.cisco.com/blog/150396/booting-cisco-router-tftp-server

2014年7月16日星期三

Cisco 2921 Integrated Services Router

Cisco 2921 Integrated Services Router is one type of Cisco 2900 Series Integrated Services Routers (ISR). Cisco 2900 series routers are designed to meet the application demands of today's medium-sized branches and to evolve to cloud-based services. They deliver virtualized applications and highly secure collaboration through the widest array of WAN connectivity at high performance that offers concurrent services at up to 75 Mbps. All Cisco 2900 Series Integrated Services Routers (ISR) have modular design that allows for reuse of a broad array of existing modules that meet business requirements while maximizing investment protection.

The Cisco 2921 delivers highly secure data, voice, video, and application services for small offices.

Features

3 Integrated 10/100/1000 Ethernet ports with 1 port capable of RJ-45 or SFP connectivity
1 service module slot
4 Enhanced High-Speed WAN Interface Card (EHWIC) slots
3 onboard digital signal processor slots
1 internal service module slot for application services
Fully integrated power distribution to modules supporting 802.3af Power over Ethernet (PoE) and Cisco Enhanced PoE
Security

Embedded hardware-accelerated VPN encryption
Secure collaborative communications with Group Encrypted Transport VPN, Dynamic Multipoint VPN, or Enhanced Easy VPN
Integrated threat control using Cisco IOS Firewall, Cisco IOS Zone-Based Firewall, Cisco IOS IPS, and Cisco IOS Content Filtering
Identity management: Intelligently protecting endpoints using authentication, authorization, and accounting (AAA), and public key infrastructure

Voice

High-density packet voice DSP module, optimized for voice and video support
Standards-certified VoiceXML browser services
Cisco Unified Border Element capabilities
Cisco Unity Express voicemail support
Support for Cisco Communications Manager Express and Survivable Remote Site Telephony

The Cisco 2900 Series offer unparalleled total cost of ownership savings and network agility through the intelligent integration of market leading security, unified communications, wireless, and application services. The Integrated Services Routers Generation 2 platforms are future-enabled with multi-core CPUs, support for high capacity DSPs (Digital Signal Processors) for future enhanced video capabilities, high powered service modules with improved availability, Gigabit Ethernet switching with enhanced POE, and new energy monitoring and control capabilities while enhancing overall system performance.

3Anetwork.com wholesales Cisco 2900 series routers, ship to worldwide. For the rich experience, among all Cisco 2900 routers, cisco2901/K9, cisco2911/K9 and cisco2921/K9 are best selling models. You can log in www.3anetwork.com for more details.