Tag Info

Hot answers tagged

6

While product recommendations are off-topic for ServerFault and I expect your question to be closed by the community in short order, I can offer two suggestions: Limiting yourself to a GUI-based system is limiting your ability to implement the best solution for your situation. Perhaps a system with a GUI will work well, or perhaps not. In spite of the ...


5

There isn't an existing DHCP option for this, so you have to add custom configuration to both the server and clients in order to support this. On the server (/etc/dhcp/dhcpd.conf), define a new option and set the value: option resolv-options code 224 = text; option resolv-options "timeout:2 attempts:4"; On the client (/etc/dhcp/dhclient.conf), define the ...


2

The dhcpd server will check for IPs by trying to ping the IP first, then assign the IP if it doesn't reply. If it does reply, it will mark the IP "abandoned". If a DHCP client tries to get an IP address, but none are available, but there are abandoned IP addresses, then the DHCP server will attempt to reclaim an abandoned IP address. If you have users still ...


2

As you discovered, you cannot declare hosts inside a class. The class declaration can only contain match or match if statements. If you want to group your client requests into classes using the class construct, you could do it something like this: class "MyHosts" { match hardware; } subclass "MyHosts" 1:10:bf:48:xx:xx:xx; # host2 subclass "MyHosts" ...


2

I've seen this a few times and so far I've seen only two reasons: The IP address the DHCP server gave is already in use by another device. Usually you'd see a DHCPNAK though. Your firewall is accepting the traffic to the dhcp server, but not the traffic back Fortunately both should be easy to test. Ping the IP address and check relevant firewalls.


2

It goes: CLIENT -> DHCPDISCOVER SERVER -> DHCPOFFER CLIENT -> DHCPREQUEST SERVER -> DHCPACK You you are missing the DHCPREQUEST before the DHCPACK in your description. If the client is on a different subnet than the DHCP server the DHCPOFFER is sent unicast to the DHCP-relay on port 67 UDP. The DHCP-relay agent broadcasts the DHCPOFFER to the ...


2

DHCP will generally keep the lease until the expiry time in an attempt to reissue the same lease to a client that reconnects later. It will only start to free up candidates when there is pressure on the scope from new clients. This allows clients to reacquire the same address when they connect again without too long an interval between sessions and gives ...


2

It is not DHCP who can do this, but PXE. An example (not necessarily useful for you) dhcpd.conf file: allow booting; allow bootp; authoritative; default-lease-time 600; max-lease-time 7200; option domain-name "domain.com"; ddns-update-style none; log-facility local7; deny unknown-clients; subnet 192.168.124.0 netmask ...


1

You are not detailing your OS so I'm assuming Linux. dhcpd does not appear to have an option or parameter for customizing the ddns server port, at least it's not in any man page I have seen. An option therefore could be to use iptables (or whatever firewall you have) to rewrite outbound packets to your dns server udp/53 or tcp/53, to the port it is really ...


1

DHCPD is not pushing updates to BIND because it does not know what DNS name to update since no DDNS hostname is defined.


1

I've looked at this before. Restarting named will flush updated data from .jnl files back to the zone file, but there's also another way.. rndc freeze <zone> but this will disable DDNS, so it should be followed with a rndc thaw <zone> to re-enable it, and should clear up the .jnl files. There's apparently a rndc sync in Bind 9.9.


1

This error occurs because scope options need to be defined in the top level of the configuration and not within any code block like a group: #This needs to be defined outside of any code block option space MSFT; option MSFT.nbt code 1 = unsigned integer 32;


1

While what you're seeing is correct behavior, your best option will probably be either to change the client identifier in the device, or its MAC address. If the server receives a DHCPDISCOVER with the same MAC and client identifier, what other method will it have to differentiate between the machines? On the server side you can check and see what the ...


1

Few (unrelated) points: - Look closely at the license - with most basic license you will see 'DMZ interface' in output of show ver , it means DMZ interface will be able to communicate ONLY with 'outside' destinations, not with other internal networks - Have you looked at inspection ? It greatly depends on ASA OS version , but under default class-map where ...


1

It's not clear to me if your DMZ DHCP clients are getting addresses from the DHCP server. If they are not, have you confirmed with the Packet Capture Wizard, not sure if you have it in ASDM 5.2, that the DHCP discovery is arriving to the ASA? It will look something like 0.0.0.0.68 -> 255.255.255.255.67. I believe you will need at least UDP port 67 ...



Only top voted, non community-wiki answers of a minimum length are eligible