Networking Solution

Solution review from Cisco, 3Com, HuaWei, Juniper, Linksys, D-Link, and others

Sunday, February 1, 2009

How to Configure NetFlow on Cisco Routers

After researching the issue I found out the Cisco NetFlow protocol allows you to analyze the traffic that pass the router, however In order to get this done we need to
Configure our routers to do a few things:

1. Install Software that analyze NetFlow
2. Enable NetFlow on the router
3. Configure the router to send the logs to a netflow analyzer server (needs to be configure before)

Once you got the server or PC up and running with a netflow software (there are a lot of free application, I used Manage Engine NetFlow Analyzer 6 which allows you to monitor 2 router for free) , We need to tell the router to send the NetFlow logs to the server, To do that here is the commands we need to type:


Router(config)# ip flow-export destination {hostname|ip_address} 9996
Router(config)# ip flow-export source {interface} {interface_number}
Router(config)#ip flow-export version 5
Router(config)# ip flow-export version 5
Router(config)# ip flow-cache timeout inactive 15
Router(config)# snmp-server ifindex persist


To monitor and Check that we configured the Router to send the logs type:

Router# show ip flow export
Router# show ip cache flow
Router# show ip cache verbose flow


Configuration Sample:

router#configure terminal
router(config)#interface FastEthernet 0/1
router(config-if)#ip route-cache flow
router(config-if)#exit
router(config)#ip flow-export destination 10.60.1.254 9996
router(config)#ip flow-export source FastEthernet 0/1
router(config)#ip flow-export version 5
router(config)#ip flow-cache timeout active 1
router(config)#ip flow-cache timeout inactive 15
router(config)#snmp-server ifindex persist
router(config)#^Z

router# copy run start
router#show ip flow export
router#show ip cache flow

Thursday, October 16, 2008

Cisco configuration of DHCP service on a Router or L3 Switch

How to Configure Windows 2008 DHCP Server to Perform Dynamic DNS Updates

By default, a Windows Server 2008 DHCP server automatically updates A and PTR records for DHCP clients that request a dynamic DNS update.


To Configure Your DHCP Server to Perform Dynamic DNS Updates

1. In Server Manager, expand Roles, and then expand DHCP Server.

2. Expand the server name, right-click IPv4, and then click Properties.

3. Click the DNS tab. Select Enable DNS Dynamic Updates According To The Settings Below.

4. To allow the DHCP server to remove resource records after a DHCP lease expires, select the Discard A And PTR Records When A Lease Is Deleted check box.

5. To perform dynamic DNS updates for client computers that are not capable of performing their own updates, select the Dynamically Update DNS A And PTR Records For DHCP Clients That Do Not Request Updates check box. Windows 2000 and all later versions of Windows can perform their own dynamic DNS updates. Click OK.

Wednesday, April 9, 2008

Cisco, Juniper face-off on software

By Jim Duffy
Network World, 06/12/00

SANTA CLARA - Speeds and feeds are not all that matters when building reliable routers for the Internet core.

Indeed, the software component of these high-speed devices may play an even larger role in ensuring that packets and sessions are not dropped. That's why Cisco is building more resiliency and redundancy into its next generation IOS software. That's also why Juniper Networks plays up the reliability of its Junos operating system.

And perhaps that's why these two rivals try to point out the deficiencies of each others' software offerings. Although Cisco has been around a lot longer than Juniper, both companies are courting the same customers in the service provider market, where Cisco is a relative newcomer.

"Juniper continues to eat away at Cisco's leading market share - which is still in the 70% range - and this trend should continue," market researcher Current Analysis stated in a recent report.

"Our broader strength is our six major releases in 18 months," says Scott Kriens, Juniper CEO, commenting on Junos. "We can deliver innovation faster than anyone else. It's that accumulated breadth that is our competitive advantage."

Eighteen months pales in comparison to 15 years, which is how long Cisco has been developing and selling IOS.

"We are the market share leader from a control plane perspective," says Martin McNealis, marketing manager in Cisco's IOS Technologies division, referring to the Multi-protocol Label Switching, VPN, voice and multicast features of the Cisco software. "We're not hearing service providers hammer the table saying we need to have [certain features] because [Juniper] has it."

It's neither Juniper nor Junos that's prompting Cisco to build more resiliency, availability and redundancy into the next major release of IOS. IOS will feature "more intelligent" handling of outages and service upgrades, McNealis says.

"We're now looking to deliver a bulletproof architecture," McNealis says. "Now that we're a systems company, we have to accept that there will be hardware and software failures."

Cisco is building stateful redundancy into IOS whereby information on the state of routes, sessions or packets can be replicated within a router chassis. Currently, Cisco offers redundancy between two distinct routers via the Hot Standby Routing Protocol in IOS.

Juniper refers to this version of IOS as IOS NG, with NG standing for "Next Generation." IOS NG is Cisco's attempt to be more competitive with Junos by having a more modular architecture and being tailored specifically for service providers, Kriens says.

Juniper's definition of modular means separate processes - such as routing protocols, management and security - each run in protected memory. Currently, IOS is "monolithic," Kriens says, meaning all processes run together and are interdependent.

"It's kind of comparing Windows with DOS," Kriens says, noting the modular nature of Windows vs. the monolithic nature of DOS.

Perhaps it's best to compare an operating system that was built from the ground up to perform routing vs. one that has its roots in a general purpose operating system such as Berkeley Sockets - the precursor to Unix - but has been modified to do routing, says Cisco's McNealis. IOS is the former while Junos is the latter.

"IOS was always tailored for infrastructure," McNealis says. "It's very network-centric. It's control plane and data plane optimization vs. a general-purpose operating system. You do make some compromises when it has to be that portable."

Juniper selected Berkeley Sockets as the source code for Junos because it was readily available in the public domain, Kriens says. But JUNOS represents 4 years and 300 to 400 man years of development on top of that Berkeley Sockets source code, he says.

"Any resemblance [to Berkeley Sockets] would be so remote as to be irrelevant," Kriens says.