I have 3 switches on a customers network. A 1900, 2900 and a 2950. I am having a problem with Win98 clients receiving a Dynamic address from a Windows 2K DHCP server. I have checked the Port fast setting and it appears that all are enabled by default. Should I disable PF for ports that have switches daisy chained or servers plugged into them? These clients can receive address by ipconfig /renew_all or when there is little activity on the switch.
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Port Fast 1
- Thread starter talcs
- Start date
You can only get DHCP addresses on the Win98 machines when you do it manually? Have you tried updating the Win98 drivers for the NIC?
Portfast should be enabled for all "host" machines connected to the switches. I would even include servers in this "host" qualification.
Portfast should be enabled for all "host" machines connected to the switches. I would even include servers in this "host" qualification.
- Thread starter
- #3
Drivers are up to date. Also there are a number of various pc brands thus limiting the chance of it being the nic. Ports are set to operate at half duplex. I have not checked each pc, but assume most are 10mb nics.
Some documentation seemed to indicate portfast should be disabled for devices such as servers and interconnected switches. Couldn't quite see the point of this.
Some documentation seemed to indicate portfast should be disabled for devices such as servers and interconnected switches. Couldn't quite see the point of this.
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- #5
Portfast shortens the whole block/listen/learn/forward cycle, but doesn't disable spanning tree. It should be disabled wherever there is a chance of a loop - switches for sure, but servers can also be an issue if they start routing/bridging. I haven't seen it cause any issues with DHCP, but definitely with IPX logon.
This might be helpful --->
-Ken
This might be helpful --->
-Ken
- Thread starter
- #8
Hi,
Ports configured with portfast do still participate in spanning tree. If the port is part of a loop it will EVENTUALLY move into blocked state. During this time there is the possibility of a loop condition, the vast increase in traffic may cause BPDUs to be dropped by the switches in the loop and the loop condition not being rectified.
Portfast should only be configured on HOST ports, not on ports that interconnect switches.
There is an enhancement to Portfast, BPDUGUARD. This effectively makes a port configured to portfast "look out" for BPDUs (a host will never send a BPDU) - if the port sees a BPDU packet it will take a configured action on that port (e.g. shutdown the port immediately).
More info is available at
Cheers,
Phil.
If everything is coming your way then you're in the wrong lane.
Ports configured with portfast do still participate in spanning tree. If the port is part of a loop it will EVENTUALLY move into blocked state. During this time there is the possibility of a loop condition, the vast increase in traffic may cause BPDUs to be dropped by the switches in the loop and the loop condition not being rectified.
Portfast should only be configured on HOST ports, not on ports that interconnect switches.
There is an enhancement to Portfast, BPDUGUARD. This effectively makes a port configured to portfast "look out" for BPDUs (a host will never send a BPDU) - if the port sees a BPDU packet it will take a configured action on that port (e.g. shutdown the port immediately).
More info is available at
Cheers,
Phil.
If everything is coming your way then you're in the wrong lane.
- Status