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NetBios issues accros VLANs

maxcue7
Level 1
Level 1

‎10-22-2004 10:55 AM - edited ‎03-02-2019 07:28 PM

Hi everyone,

I have implemented a new network with 2-3550s as the L3 core, 3-3750s L2 for the workstations, 1-2970 (new server switch) and a 2924M-XL(old server switch) for the servers. Each of the access switch has links to both the 3550s. I have segmented the network into different vlans.

VLANS

workstation - 10, 20

new servers - 30

old servers - 1

I am in the process of migrating the old network to the new network so right now both of the networks exist together.

The problem is a little wiered and not consistent. All the workstations exist on the new 3750 in vlan 10 & 20 and the servers on the old 2924M-XL in default vlan 1.

All the vlan interfaces have been configured with a IP-helper address pointing to a new win2003 dhcp server in vlan 30. The dhcp points the workstations to a Windows NT PDC on 2924M-XL vlan 1 for its WINS and DNS resource.

Now when I open My Network places on a workstation in vlan 10, some see all the PC's on that vlan whereas some see only the servers on vlan 1.

The workstation can resolve netbios names of both Wkstations and Servers whereas when I ping the a workstation from the PDC with its netbios name, it doesn't resolve it.

Its really inconsistent.

And for the network to perform properly all the servers should be able to resolve WkStation names and vice-a-versa.

I checked the WINS database and it has fresh entries of all the WkStations and Servers.

Can somebody please help me figure out what the problem is, if I am missing something or I need to configure the 3550 for some kind of statement.

Thanking you in Advance

Jeetu Bhatia

Network Engineer in Canada

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0 Helpful
4 Replies 4

sean
Level 3
Level 3

‎10-22-2004 01:36 PM

Did you try enabling NetBIOS over TCP/IP on the workstations?

0 Helpful

maxcue7
Level 1
Level 1
In response to sean

‎10-22-2004 11:34 PM

It is enabled.

0 Helpful

Prashanth Krishnappa
Cisco Employee
Cisco Employee

‎10-23-2004 12:26 AM

Have you configured "switchport host" under the interfaces on which you have workstations on the 3750? If not, can you enable this and try?

0 Helpful

andrew.butterworth
Level 7
Level 7

‎10-24-2004 06:35 AM

It sounds like it may be a master browser issue. When you enable IP Helpers there are 9 UDP broadcasts that are enabled by default: bootpc (client udp 68), bootps (server udp 67), tftp (69), IEN116 name service (obsolete, UDP 42), DNS (53), time (37), netbios name server (137), netbios datagram service (138) and tacacs (49). If you don't disable the netbios broadcast forwarding you can get master browser issues (there should be some logged in event viewer on the DC at least). I generally disable the unwanted protocols after enabling any IP Helpers.

no ip forward-protocol udp tftp

no ip forward-protocol udp nameserver

no ip forward-protocol udp domain

no ip forward-protocol udp time

no ip forward-protocol udp netbios-ns

no ip forward-protocol udp netbios-dgm

no ip forward-protocol udp tacacs

With Windows 2000/2003/XP you don't actually need NetBIOS anymore since you can publish any shares in Active Directory. This can be a bit frustrating for users though since browsing Network Neighborhood no longer works, but UNC's do. There is an article here:

http://www.win2000mag.com/Articles/Index.cfm?ArticleID=21537&pg=1

Good luck

Andy

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