- Community Home
- >
- Networking
- >
- Switching and Routing
- >
- Comware Based
- >
- Users are not assigned IP address through DHCP whe...
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-29-2013 05:32 AM - edited 06-03-2013 08:28 AM
05-29-2013 05:32 AM - edited 06-03-2013 08:28 AM
Users are not assigned IP address through DHCP when switching VLANs or even switchports.
Hello All,
I've got a HP 7503 with DHCP enabled on several VLANs.
There's a strange issue going on.
We have some users that are wired to their desks.
Eventually, they move to any of our meeting rooms and plug their laptops on the wired connection avaliable.
When they get back to their desks, they got no network connectivity.
They do get DHCP address settings, but they're unable to ping their gateway.
I need to do the his procedure.
- Log on the access switch CLI and clear that mac-address from the mac-address table.
- Also, i have to logon to my L3 switch and clear the mac-address from the mac-address table and remove the arp entry from my mac-address.
So, i'm wondering if this is a spoofing protection or a bug.
If it's not a bug, how do I turn it off?
This is causing a lot of problems to the users.
Any advice is much appreciated.
Best regards.
- Tags:
- DHCP
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-30-2013 03:05 PM
05-30-2013 03:05 PM
Re: Users are not assigned IP address through DHCP when switching VLANs or even switchports.
That sounds very strange indeed. If you post your configuration and any log messages relating to those ports it might help get to the bottom of things.
Paul
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
06-03-2013 10:50 AM - edited 06-03-2013 10:50 AM
06-03-2013 10:50 AM - edited 06-03-2013 10:50 AM
Re: Users are not assigned IP address through DHCP when switching VLANs or even switchports.
Hello Paul,
Thanks for your reply.
Apparently it's an issue with one of our Cisco phones (7492).
The phone is not releasing the Mac-address from it's table after the users disconnects from the PC port.
<CWB_N01_R06_P01>dis mac-address b888-e3e0-aa3b
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
b888-e3e0-aa3b 152 Learned GigabitEthernet2/0/6 AGING
b888-e3e0-aa3b 152 Learned GigabitEthernet4/0/17 AGING
When this happens, users have no L2 connectivity until I unplug the phone from the network or clear the mac-address entries for this mac.
We also have other Cisco phone models, but they are working fine.
Cisco 6921, for example, correctly "migrates" the mac-address after disconnecting from one phone and reconnecting to other phone.
[CWB_N01_R06_P01]dis mac-address b888-e3e0-aa3b
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
b888-e3e0-aa3b 152 Learned GigabitEthernet2/0/3 AGING
--- 1 mac address(es) found ---
*** Disconnected and reconnected on other switchport - The mac has moved correctly ***
[CWB_N01_R06_P01]dis mac-address b888-e3e0-aa3b
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
b888-e3e0-aa3b 152 Learned GigabitEthernet2/0/6 AGING
--- 1 mac address(es) found ---
We'll try to upgrade the phone firmware.
if that does not work, I'll probably have to decrease the Mac-address aging time to 30s.
Thanks and regards.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
06-06-2013 02:55 PM
06-06-2013 02:55 PM
Re: Users are not assigned IP address through DHCP when switching VLANs or even switchports.
I'm not convinced this is the right track to be pursuing with this problem.
When a switch learns a MAC through two different ports, it should send packets for that MAC out *both* ports, so until the old port has aged, everything should continue to work. Even if the switch has an extra port for that MAC, it should still behave correctly.
If it is a MAC aging issue, then if you leave the device on the new port for a while and wait for the old MAC table entry to expire, it should start working. Does this happen? If not, then i think it has nothing to do with MAC tables. What concerns me more is that you have to also remove the ARP entry to make it work, especially since the ARP entry shouldn't change if they're on the same VLAN.
Paul