New engineers will sometimes find themselves confused when it comes to the differences of defining a route. When to use ip default-gateway and ip default-network and lastly when to use ip route 0.0.0.0 0.0.0.0 [interface] Below is brief breakdown between the three.
1) Default Gateway (ip default-gateway x.x.x.x)
This command serves non-routing network device that need to reach any network outside its own subnet or outside of its local network. The command is to function when the network device is not in routing mode. Typically the command exists in Layer-2 switches or switches that are in bridging mode only. In order for this command to function in a router, ip routing must be disabled. When the ip routing is disabled, the router becomes merely a host, similar to your regular PC. To reach any network outside its own subnet or outside of its local network, the device needs to have a default-gateway.
2) Default Network (ip default-network a.b.c.d)
This command establishes a default subnet or network for specific routing-speaking network device. Therefore the ip routing must be enabled on the device.With this command in place, your Layer-3 network device will actually route packets unlike the default-gateway command. Second this command does not specify the next hop address, it specifies a network to be considered as default. In order for this command to set a default network, you must already have a static route in your routing table. You can tell if this is working if from a sh ip route there is a “gateway of last resort” configured.
3) Gateway of Last Resort (ip route 0.0.0.0 0.0.0.0 next-hop-ip/exit-interface)
This command also requires ip routing to be enabled. This command sets a default route for anything not in your routing table. After this command is entered it will show a “gateway of last resort” configured in your ip route table.
Keep moving along folks there is really nothing to see here…. nothing really new to report here, people always said the end was near, the real news is that they thought this day would have taken place 8 years earlier. .. below is my brief editorial of what took place Feb 3 2011.
AfricNIC, APNIC, ARIN, LacNIC and the last of the last goes to RIpeNCC
http://www.nro.net/media-center/video-archive-3-february-2011 < video press conference here.
Side note, APNIC has half of the worlds population and the majority of the IP4 addresses.
APNIC walked away with three /8 blocks (2 which were received earlier this year)and predict that it will hand them all out within the next 3 to 6 months.
A side note;
OSPF (Open Shortest Path First) has many configurable topologies. One of being the Stubby Area, as if that didn’t confuse you enough they introduced the Totally Stubby Area when this was first explain to me, I couldn’t grasp the concept of what the instructor was talking about, at least not until I drew the network out and configured it out in GNS3, it was then I was able to seen it for myself.
FYI OSPF overview, stubby networks only used for a small area that need to block all the external routes in their routing table. Routing will show a default internal route pointing to their ABR. Generally in the OSPF world all things must connect to Area 0, the ISP link would normally flow out Area 0 ASBR I think of Area 0 as the OSPF body and other area as limbs (the analogy works for me). Click topology for larger pic.
Many AVAYA products have already moved to the System Platform base (and the rest of them except CMS will move to SP by end of year). System Platform is a “virtual server” environment… there is one VERY CRITICAL “feature” that everyone who potentially works on an AVAYA SP based product needs to know. In the past, you could go into most products and make a change to the time (CM, AES, MM, etc) and the system would restart it’s time service or NTP service and you were good to go.
It’s funny at what you find when Googling for help. I ran across this cartoon while searching for “Virtual Windows Machines Network” . I decided to re-post it here, the site’s URL and link is provided at the bottom, Not a bad place to visit on a slow network day.
A while ago I stumbled upon a great piece of code that could make your Cisco router a little less intimidating for your tier one tech support staff. The tier one team is useless the first ones that the customer engages when calling in a trouble.
Most of the time tier one is responsible for taking the customer information, creating a ticket and performing some basic trouble shooting steps, i.e. verify links and change passwords or provide application assistance, anything more in depth is forwarded to the tie 2 or 3 group.
With a simple menu configured on a Cisco router you can perform basic show commands that any tier 1 or 2 can use without the fear causing any intrusive down time to the production network, and the person performing the commands does not need to know the proper command syntax .
It’s been a busy six weeks for me. I got the crazy idea of putting together some short five to ten minute how-to ConfigBytes video casts, I’m just polishing up the last frames of my video podcast debut. I decided to create these from watching several others that ether fall short or are out dated.
There is nothing more frustrating than watching a configuration video that someone placed on YouTube with NO sound or at least a commentary of what they are doing. What I found is that these are freaking hard to make, trying not to stutter and remember to look up at the camera ever now and then were the hard parts then threes video and sound editing along with fact checking (making sure that the config you type is correct)
I hope to have the first video in the can by the end of this month. My goal to create one a month based on the amount of feedback I get I can see me doing one a week.
I received a faulty ASA 5505 from a customer the other day. Customer has already been shipped a replacement and now I asked what should I do with this one, sitting on my desk. The problem with this device is that the power plug had become loose, periodically causing the ASA to reload and causing havoc on the customer’s network. It clearly had to be replaced
Normally I would send a refurbished non smart net covered Cisco item out for repair, if the cost was justified. ASA 5505 can be purchased from Bay for around 375 bucks used and 600 new; cost to repair this plus shipping would have been close to $200. In this case it was better to simply replace it. I decided to crack this box open and take a peek inside. I feel comfortable doing this because my previous career was an electronics bench tech. Continue reading
Just received our first Juniper router, a J2300; this will be added to our lab along with the Extreme Summit and the rest of Cisco gear. At first glance the J2300 looks like any other device that will fit a 19in rack. The first thing I had to do was pop the top off and see what made this tick. As you can see from the following picture there not a whole lot in here. The box appears rather empty, I did notice a beefy processor and a standard compact flash.
The power supply is 250watt, not much going on here, than again you really don’t much to drive this thing.
root@J2300> show version
JUNOS Software Release [7.1R1.3] (Export edition)
I’ll continue my updates through the month as I slowly configure the router. One thing I did notice is that you realy dont need to console cable, the router has it own built in management web GUI that is connected to 192.168.1.1. The code DOES not look like you typical Cisco config, it looks more like programmers code, like C, perl or PhP.
The Juniper 2300 will be a challenge that I look forward to. Check back for more updates on the J2300.
So far I am not pleased with the new GNS3 07 , I’m having some serious issues in rying to configure the settings.
Searching the internet has not yeilded much information on how to set this up. This week I’ll be “plunking” around with the new GNS3, trying to make it work. I hope to have it all figured out soon so I can upload my PIX labs that I’ve been working on.