OSPF question- network statement
In the ACRC book (page 200), the author shows the 10.64.0.1/24 network being placed into an area 0 with the command: network 10.64.0.1 0.0.0.0 area 0 Why is the wild card mask 0.0.0.0 used and not a mask which matches the actual manner in which the network has been subneted? Is there any difference to the operation of the router, area, OSPF, or area routing if the above was changed to: network 10.64.0.1 0.0.0.255 area 0 ? If the above two forms result in identical operation, why is the wild card mask required? Thanks, Brian ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
I've got a lot to learn in this arena, but I remember puzzling over that until I got to the next page. The last sentence of the description of the use of the wildcard-mask notes that you can specify an interface address by using the wildcard mask 0.0.0.0--and given the linear arrangement in the diagream, a single interface makes sense to me. If it still doesn't to you, we can talk more off-line if you like. HTH Annlee ""Field, Brian"" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > In the ACRC book (page 200), the author shows the 10.64.0.1/24 > network being placed into an area 0 with the command: > > network 10.64.0.1 0.0.0.0 area 0 > > Why is the wild card mask 0.0.0.0 used and not a mask > which matches the actual manner in which the network > has been subneted? Is there any difference to the operation > of the router, area, OSPF, or area routing if the above was > changed to: > > network 10.64.0.1 0.0.0.255 area 0 > > ? > > If the above two forms result in identical operation, > why is the wild card mask required? > > Thanks, > Brian > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
he wanted to show that you can use the whole network 10.0.0.0 in an area.notice he use 255.255.255.255 as the mask of the area meaning everthing or he could have 10.0.0.0 0.255.255.255 area 0 or 10.64.0.1 0.0.0.0 area 0 or 10.64.0.0 0.0.0.255 area 0 notice in the side hes states that you can define the network or an interface. "Field, Brian" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > In the ACRC book (page 200), the author shows the 10.64.0.1/24 > network being placed into an area 0 with the command: > > network 10.64.0.1 0.0.0.0 area 0 > > Why is the wild card mask 0.0.0.0 used and not a mask > which matches the actual manner in which the network > has been subneted? Is there any difference to the operation > of the router, area, OSPF, or area routing if the above was > changed to: > > network 10.64.0.1 0.0.0.255 area 0 > > ? > > If the above two forms result in identical operation, > why is the wild card mask required? > > Thanks, > Brian > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
Brian, In OSPF, the network statement activates OSPF routing on the interfaces that match the address + mask combination. The wildcard mask DOES NOT have to match the subnet masks used on interfaces. Consider the following config: int e0 ip addr 10.64.0.1 255.255.255.128 int e1 ip addr 10.64.0.129 255.255.255.128 router ospf 1 'network 10.64.0.1 0.0.0.0 area 0' only activates OSPF on e0 and not e1. 'network 10.64.0.1 0.0.0.255 area 0' activates OSPF on BOTH e0 AND e1. HTH, Scott "Field, Brian" wrote: > > In the ACRC book (page 200), the author shows the 10.64.0.1/24 > network being placed into an area 0 with the command: > > network 10.64.0.1 0.0.0.0 area 0 > > Why is the wild card mask 0.0.0.0 used and not a mask > which matches the actual manner in which the network > has been subneted? Is there any difference to the operation > of the router, area, OSPF, or area routing if the above was > changed to: > > network 10.64.0.1 0.0.0.255 area 0 > > ? > > If the above two forms result in identical operation, > why is the wild card mask required? > > Thanks, > Brian > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] -- >> Scott F. Robohn, CCSI #20826, CCNP/CCDA.703-623-3752 << >> Chesapeake Network Solutions.mailto:[EMAIL PROTECTED] << >> mentor:technologiesmailto:[EMAIL PROTECTED] << ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
>In the ACRC book (page 200), the author shows the 10.64.0.1/24 >network being placed into an area 0 with the command: > > network 10.64.0.1 0.0.0.0 area 0 > >Why is the wild card mask 0.0.0.0 used and not a mask >which matches the actual manner in which the network >has been subneted? Is there any difference to the operation >of the router, area, OSPF, or area routing if the above was >changed to: > > network 10.64.0.1 0.0.0.255 area 0 > >? > >If the above two forms result in identical operation, >why is the wild card mask required? > >Thanks, >Brian > By making the mask specific enough to match the router interface only, it makes troubleshooting and maintenance easier. While it is possible to have masks that meet multiple router interfaces, my experience tells me that configurations are most clear if there is 1:1 correspondence between network statements and OSPF-speaking router interfaces. ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
If you look further to page 201 in the description for the network / area command 0.0.0.0 is used to specify that the mask uses the interface address If you look at RouterA it uses an inverse mask network 10.0.0.0 0.255.255.255 area 0 but look at RouterB, it uses network 10.64.0.2 0.0.0.0 area 0 now look at the interface configuration, ip address 10.64.0.2 255.255.255.0 in this case the "0.0.0.0" will be interpreted as 0.255.255.255 sort of a shortcut if the router has multiple interfaces. Kevin Wigle CCDA CCNA CBE CBI MCSE - Original Message - From: Field, Brian <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, 10 May, 2000 21:59 Subject: OSPF question- network statement > > In the ACRC book (page 200), the author shows the 10.64.0.1/24 > network being placed into an area 0 with the command: > > network 10.64.0.1 0.0.0.0 area 0 > > Why is the wild card mask 0.0.0.0 used and not a mask > which matches the actual manner in which the network > has been subneted? Is there any difference to the operation > of the router, area, OSPF, or area routing if the above was > changed to: > > network 10.64.0.1 0.0.0.255 area 0 > > ? > > If the above two forms result in identical operation, > why is the wild card mask required? > > Thanks, > Brian > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF question- network statement
the 0.0.0.0 denotes the specified address only. RouterA int s0 ip addr 172.21.1.10 255.255.255.0 int s1 ip addr 172.21.2.20 255.255.255.0 int s2 ip addr 172.21.3.30 255.255.255.0 Ex. 1 router ospf 1 network 172.21.1.10 0.0.0.0 area 0 network 172.21.2.20 0.0.0.0 area 0 network 172.21.3.30 0.0.0.0 area 0 Ex. 2 router ospf 1 network 172.21.1.0 0.0.0.255 area 0 network 172.21.3.0 0.0.0.255 area 0 Ex. 3 router ospf 1 network 172.21.0.0 0.0.255.255 area 0 Ex. 1 just routes the subnetted network by using interface address. You can then just "shutdown" specified interface to stop ospf routing for network/interface instead of "no router ospf 1", which in a crunch, you might forget to cut and paste into text editor. Otherwise you'd have to show startup-config, and wait for config to show on screen, and then cut and paste. Ex. 2 will enable routing entries for entire subnet, which might cause a problem if you make a mistake of adding an ip address in specified subnet on another router interface. Ex. 3 to summarize all 3 subnets Tom Trygar Kevin Wigle wrote: > If you look further to page 201 in the description for the network / area > command > > 0.0.0.0 is used to specify that the mask uses the interface address > > If you look at RouterA it uses an inverse mask > > network 10.0.0.0 0.255.255.255 area 0 > > but look at RouterB, it uses > > network 10.64.0.2 0.0.0.0 area 0 > > now look at the interface configuration, ip address 10.64.0.2 255.255.255.0 > > in this case the "0.0.0.0" will be interpreted as 0.255.255.255 > > sort of a shortcut if the router has multiple interfaces. > > Kevin Wigle > CCDA CCNA CBE CBI MCSE > > - Original Message - > From: Field, Brian <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, 10 May, 2000 21:59 > Subject: OSPF question- network statement > > > > > In the ACRC book (page 200), the author shows the 10.64.0.1/24 > > network being placed into an area 0 with the command: > > > > network 10.64.0.1 0.0.0.0 area 0 > > > > Why is the wild card mask 0.0.0.0 used and not a mask > > which matches the actual manner in which the network > > has been subneted? Is there any difference to the operation > > of the router, area, OSPF, or area routing if the above was > > changed to: > > > > network 10.64.0.1 0.0.0.255 area 0 > > > > ? > > > > If the above two forms result in identical operation, > > why is the wild card mask required? > > > > Thanks, > > Brian > > > > ___ > > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > > FAQ, list archives, and subscription info: http://www.groupstudy.com > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
