From the monthly archives: January 2009

Cisco: OSPFv3 point-to-point network configuration

By On January 29, 2009 · 2 Comments

In the previous post I explained some basic stuff about IPv6 and how to configure IPv6 addresses on Cisco’s interfaces. Following this subject, I want to explain now how you can configure unicast dynamic routing protocols for IPv6 networks. The same as IPv4, the v6 generation of IP addresses supports routing protocol like OSPF, RIP and EIGRP, just that their names has been adapted to the v6 generation meaning OSPFv3, RIPng and EIGRP for IPv6.

From the routing protocols above I chose for today [...]

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Cisco: IPv6 basics and configuration how-to

By On January 27, 2009 · 4 Comments

Today, I had to deal with IPv6 configuration for my CCIE preparation and I said to write a small tutorial about IPv6 for it’s basic stuff. First of all IPv6 is not more complicated that IPv4, it just look like it is. Second, and this is my personal opinion, I think that as long as IPv4 will be on the market and things like NAT can overcome the problem of  IP addresses being exhausted, IPv6 will not be implemented on a large scale. Let’s be [...]

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Cisco Security Manager Vulnerability

By On January 21, 2009 · Leave a Comment

Cisco Security Manager contains a vulnerability when it is used with Cisco IPS Event Viewer (IEV) that results in open TCP ports on both the Cisco Security Manager server and IEV client. An unauthenticated, remote attacker could leverage this vulnerability to access the MySQL databases or IEV server.

Reat the full post on cisco.com…

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Cisco: Use CBAC to achieve firewall functionality on router device

By On January 19, 2009 · 4 Comments

Sometimes, because of cost saving usually, the network engineers are forced to use a Cisco router as a firewall (instead of Cisco PIX or ASA). One of the big difference between router and firewall devices is that the ports have different characteristics. If on routers, ports are permitting by default traffic of any packets in and out, on the firewall devices, any packets are denied, if not explicit permitted.Also firewalls look at ports as Inbound at Outbound while for routers this has no meaning.

Anyway [...]

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Cisco: Engineer’s trick to avoid suboptimal path

By On January 16, 2009 · 9 Comments

I was explaining in the previous post what is the difference between optimal and suboptimal path and how to avoid the use of not such a good path in your routed environment. Also there I presented this so call “dirty trick” you can use to force the routing protocol to choose the path that you want, based on the Administrative distance modification.

As I said there is another way (for sure more than one) to do it, using [...]

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Cisco: Dirty trick to force optimal path in routed environment

By On January 15, 2009 · 3 Comments

Everywhere in the world people try to find the optimal path to achieve something.If we speak about roads, trips and in our case networking, choosing the best path to an end point can have only advantages.

I took the term optimal / suboptimal path from the routing issues that can appear in the OSPF network environment and which are called by the experts suboptimal routing. What I want to explain here, maybe you already seen it, is that in some network environment the best path [...]

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Cisco 7600 series

By On January 15, 2009 · Leave a Comment

[flashvideo filename=http://www.firstdigest.com/vid/archive/2009/01/cisco7600.flv image=http://www.firstdigest.com/vid/archive/2009/01/cisco7600.jpg /]

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Cisco: Layer 1 link failure detection

By On January 12, 2009 · Leave a Comment

It has been a while since I didn’t post anything here, but it was holidays and I used that time to relax and rest after a year of work. Following this idea I wish you all “Happy New Year” and all the best in 2009.

Today I planned to write about something easy to implement (just to get in shape), but ignored by some network engineer. For me, Layer 1 issues are very annoying, and here I’m talking mostly about the cases when everything look [...]

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