"route delete" fails 1

[Kkto]

Hi there.

I'm developing a tool for transmitting/receiving UDP packets thru 2 Ethernet cards (from one to another, i mean). I'm using Win98.

I don't want them to see each other, but when i try to delete the route from the route table with &quot;route delete <ip.addr>&quot; i get an error saying &quot;Couldn't find route&quot;...

...and, of course, when typing &quot;route print&quot; i DO find route...

Can someone help me?


Thanx a lot.

 

[ChicagoTechNet]

this may help. quoted from

http://www.ChicagoTech.net

&quot;The Route Addition Failed: 87&quot;

Symptom: When running route command, you may receive above error message.

Resolution: make sue you enter the correct information such as destinations, mask and router. Use route /? to get more detail.


Robert Lin, MS-MVP, MCSE & CNE
Windows, Network and How to at

http://www.ChicagoTech.net

 

[Kkto]

Yes, i got that error msg when adding a route...

But i still can't erase a route.

I've trying in Windows ME, with following table:

>route print
Destination Mask GW IF
...
138.4.255.255 255.255.255.255 138.4.8.35 138.4.8.35
...

>route delete 138.4.255.255
The route specified was not found.

>route delete 138.4.255.255 mask 255.255.255.255 138.4.8.35
The route specified was not found.

-----

??

 

[ChicagoTechNet]

how can you have 138.4.255.255? try this: route -f command and post back with the result.

Robert Lin, MS-MVP, MCSE & CNE
Windows, Network and How to at

http://www.ChicagoTech.net

 

[Kkto]

138.4.255.255 was one of the routes in a comp i was trying.

The one i want to run is a standalone comp with 2 eth cards: 10.0.0.1 and 11.0.0.1

I tried &quot;route -f&quot;, but fails too: &quot;The route specified was not found&quot;.

 

[Kkto]

138.4.255.255 was one of the routes i found in a Win ME, not my comp.

The comp i'm using is a standalone Win 98 with 2 eth cards, using IP 10.0.0.1 and 11.0.0.1.

I tried route -f, but fails too: &quot;The route specified was not found&quot;, which does not make sense for me...

 

[John Lewis]

The x.x.x.255 is not a 'real' route. It is a broadcast route generated internally. For instance, if you added a route (either manually, from an existing persistent route, through a dhcp configuration, etc) to 138.4.0.0 mask 255.255.0.0, a broadcast route for 138.4.255.255 will be created. You should receive an error if you try to create a similar route manually, as routing must be targeted at a network or a host, not a broadcast. Most versions of Windows will maintain the broadcast route even after the 'real' route is deleted. It will not go away until you restart Windows.

The good news is, it really doesn't matter. This route will not allow any data to pass without a related 'real' route.

So the question would be, are you seeing a problem associated with the situation, or are you assuming there will be a problem because the table looks odd?

On another note, the 11.x.x.x address is not a good idea. If you ever connect these machines to the internet, you could see some unexpected results as that adress is a public IP.

 

[Kkto]

Well, the comp will be always offline. It will be only connected to itself, not a router, nor a hub, nor internet or anything.
Basically, it's just a private network between the 2 eth cards; so IP 10.x & 11.x won't matter, i guess.

What i'm trying to do is a loop so i can send data thru cable from one IP to the other and see how much data reaches destination. It's just for educative purposes only: i want students to see how much noisy the connection can be and still get data received. And that's why i wanna disable loopback interface, because i can't control that signal.

Looking at the route table, i found that the route from 10.0.0.x to 11.0.0.x is 127.0.0.1 and i can't erase that. So, sending UDP packets from 10. to 11. always reach destination without any signal on cable.

Hope this explanation helps.

Thanx a lot

 

[John Lewis]

Afraid you won't be able to do what you want.

The loopback IF is built into the TCP/IP core, you can't delete or disable it without some really extreme measures. If you were to get it disabled, you would be amazed at how many Windows components would stop working, a lot of things use the TCP/IP stack internally when it is installed.

Any time you install two (or more) network cards with a MS OS and TCP/IP, routes are created as each interface is initialized pointing to the loopback IF, so any time you send data destined for an IF that is internal to the machine, it is picked up by the loopback before it ever hits hardware.

 

[opediggitty]

I think to show your students that you can transmit UDP traffic with other traffic on the line, you should use 2 computers with a crossover cable in between them and assign the 10.x.x.x on one and the 11.x.x.x on the other.