Cannot see network but can access it

[azazippo]

Hi all,

I have the following setup:
- two PCs: A and B (REPLICON & URIEL)
- they are part of the same workgroup, NRTAN
- IP: A -> NNN.NNN.NNN.180 and B -> NNN.NNN.NNN.195 (assigned by the local admin)
- same subnet mask for A and B: 255.255.255.0
- same default gateway for A and B: NNN.NNN.NNN.254
- same 3 DNS servers for A and B
- no direct connnection with crosslink
- both PCs have Win Xp pro, A has Sp1, B has Sp1 and 2, both have NTFS file systems
- logged on as Administrator in both cases
- file sharing enabled on each pc, and they both have something to share
- Windows firewalls are off
- Kerio firewalls are running, with permissions to let communicate computers within the trusted zone
- A and B both see Internet through the network
- A and B can ping each other succesfully

Yesterday - using the LAN - I've managed that A could see the workgroup computers, but cannot see B. Although I could acces B from A after I've added "\\<IP_of_B>\Pub" to Network Places through "Add new network place" in A. Still that day B could not see the workgroup computers, as the error message stated: "<workgroup> is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. The list of servers for this workgroup is not currently available."

I'm pretty sure, that it is not a workgroup-administrator issue, since the same error massage was popped up, when A and B were previously connected directly, through a crosslink cable, and the local network was excluded entirely (no internet access). That time, again, only A could access B, but not in turn.

I've tried a lot of things, and even made various permissions in Administrative Tools, but cannot remember all of those. In global, I've not advanced a bit.

Today I've made some changes to B. You may kill me but I won't know what was it, it has been lost among zillions of ineffective modifications. As you can see, now B can acces the workgroup, but A can't. As I've mentiond, after that I've changed settings in B...
Perhaps, I've restored a previous TCP/IP configuration with NetSwitch 2.0 in B. But it must be noted, that the restored settings were (or should be) the same as those that were overwritten by this restoration. Anyway, after this, B could access workgroup (but not A). It would be good to know, what exactly those data that NetSwitch saves...

So the actual situation is:
- A and B both see Internet through the network
- A and B can ping each other succesfully
- A cannot access workgroup when hitting "View workgroup computers" ("<workgroup> is not accessible. You might not have permission to use this network resource. ...")
- thus A cannot see B in "View workgroup computers", but can access it, through the previously added "\\<IP_of_B>\Pub" in "Network Places"
- B can see A
- B can see ten other PCs of the workgroup
- B cannot access A (due to "<computer> is not accessible. You might not have permission to use this network resource. ...")

- whether B is shut down or not, A cannot access the workgroup network.
- whether A is shut down or not, B can access the workgroup network.

I'm not sure, but as I recall, B could make the network connection either with subnet mask NNN.NNN.NNN.0 or NNN.NNN.NNN.128. Does this mean anything?

Any help would be greatly appreciated,
as i've lost a few calm-points in this adventure-game.

[juniper]

A cannot see B in "View workgroup computers" actualy network neighborhood and such use Netbios and not IP

but can access it, through the previously added "\\<IP_of_B>\Pub" in "Network Places" This is because of XP security, it no longer allows null sessions and enumeration by default so you have to path to the share as it can not enumerate the shares as anonymous (simple terms you must manualy give anonymous guest writes)

[azazippo]

Thanks for replying so fast Juniper.

That last sentence was rather caballistic for me. I'm an acolyte, you know.
You mean that I have to manually enter (in B) the target network places of A, as I've done it in the opposing direction? If that's what you said: I've tried that already, with no success.

To narrow down this problem to 3 questions:
1. Why is it that A cannot see B, but can access it?
2. Why is it that A cannot see the other computers of the workgroup, as B does (same OS!)?
3. Why can't I access A from B?