SA520 DHCP Leased IP

[acibat0530]

Hi Guys,

Just query with regrads to the leased IP on SA520.

We have VLAN created named VLAN20 for wireless users.

Cisco AP541N is our WAP.

SA520 Configuration:

VLAN 20 DHCP IP POOL: 192.168.10.2 - 192.168.10.250
255.255.255.0

Gateway: 192.168.10.1

Lease time: 72 hours

It was working for over 2 months now until the users cannot get into the wireless due

to IP is not available. I tried to look at the DHCP leased clients on SA520 and seems all the
192.168.10.2 - 250 are used. I am not sure if the router is leasing an IP properly, no idea to be honest.

Temporary Solution:
I created a different VLAN (VLAN50)

VLAN 50 DCHP POOL: 192.168.50.2 - 192.168.50.250
255.255.255.0
Gateway: 192.168.50.1

I moved the Wireless AP on that VLAN and then all the Wireless Client can get an IP so quickly and get an internet access.

Why that happened? Is there a way how to delete leased IPs?

Thank you

AC

[rmanthey]

Hello acibat0530,

What firmware version are you on?

Cisco Small Business Support Center

Randy Manthey

CCNA, CCNA - Security

[acibat0530]

Hi Randy,

It's on the latest firmware 2.1.71 (I assume this is the latest one)

The Small Business guy told me to reboot the router and I did but the Leased IP for VLAN 20 stays there.

Can you advise please. Thank you.

AC

[rmanthey]

I do know this was a problem in an older firmware, but it was supposed to be resolved several versions ago.

Is it possible to reflash the firmware and factory default?

I know this will wipe out the DHCP table just because of the factory default, but I am not sure if there is latent code in the SA from the old firware.

do you still have a case open and what is the status?

Cisco Small Business Support Center

Randy Manthey

CCNA, CCNA - Security

[doug_counsil]

Randy,

The exact same thing occurs on our SA540.  DHCP leased clients are NEVER released/deleted.  The only way to clear them is to set the router to factory defaults.  This is definitely a bug.

We are on the latest firmware, and we haven't opened a case.

[doug_counsil]

Randy,

Do you know if there is a firmware maintenance release in the work for the SA500 Series routers?  We would like to test out a Beta version if one exists because there are a few bugs (upnp not always coming up after a reboot, SSL VPN support for Mac OSX Lion, soon Mountain Lion, etc.) and enhancements (inter-VLAN ACLs like the RV220W is getting ) that we are looking forward to getting fixed/resolved/added in the next firmware release.

[acibat0530]

Hi Randy / Guys,

They also recommend same thing:  set to factory default. The other thing I did

for temporary solution is to delete the problematic VLAN 20 and all the IP Leased for this VLAN 20

are all gone and re-create VLAN 20 again using the same IP range. Right now the router on this VLAN 20

is leasing an IP but I don't know until when, it might probably do the same behaviour unless Cisco come up

with a fixed solution.

The workaround above is not a solution, there must be something to be done on the SA520.

Thanks.

AC

[rmanthey]

Hello everyone,

I don't see a currenlty known issue for this in the current release. In an old release yes. My suggestion if you have reflashed the firmware and factory defaulted and are still having the issue come back, then to call into the support center at 1-866-606-1866 and open a case.

Thanks,

Cisco Small Business Support Center

Randy Manthey

CCNA, CCNA - Security

[florenm1970]

Randy, the easiest way to remove/reset the DHCP Leased Clients in SA520W is by updating the IPv4 LAN ending IP address. For example, I set mines to a lower value compared to max value I have it previously set (i.e. 192.168.1.15 instead of 192.168.1.16). There is no need to factory reset the router or even do a reboot.

Regards,

Floren

[rmanthey]

Hello acibat0530,

Do you have a case number I can reference?

Cisco Small Business Support Center

Randy Manthey

CCNA, CCNA - Security

[acibat0530]

Hi Guys,

Just to update you on this case. I reset the SA520 to factory default and reconfigure it again as the

Small Business tech guy.

• This solved the DHCP issue, however I don't know when it will last. If all the IPs are being used hope it will
  

renew and lease it, otheriwse, back to square one.

• Resetting it also solved problems like dropping packets on other VLANS.
  
• Internet connection becomes faster compared before the reset.
  

Hope this will help others. Thanks.

AC

[doug_counsil]

We are running the latest beta firmware release (2.2.0.3_1) on our SA540 and leased clients still aren't being released from the table (even after a reboot).

Floren's workaround above still works though:

"Randy, the easiest way to remove/reset the DHCP Leased Clients in SA520W  is by updating the IPv4 LAN ending IP address. For example, I set mines  to a lower value compared to max value I have it previously set (i.e.  192.168.1.15 instead of 192.168.1.16). There is no need to factory reset  the router or even do a reboot."