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Cannot set Next Server IP Address in DHCP server

  • desdray
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24 Jan 2021 20:05 #98284 by desdray
Model Name : Vigor2860ac
Firmware Version : 3.8.9.7_BT
Build Date/Time : Dec 23 2019 14:26:57

I'm trying to setup a TFTP server on my NAS box, 192.168.1.6 (static IP), so I would like to configure the router DHCP function to support this

Using page LAN->General Setup->DHCP Server Option, there is a box labelled 'Next Server IP Address/SIAddr'.

So I type in "192.168.1.6" (no quotes) and hit OK, below. The page refreshes and the value has disappeared from the box.

What is going on? What are valid values for this box?

BTW, I can add other DHCP options, I have these configured:
66 192.168.1.6
67 pxelinux.1
150 192.169.1.6

Using a DHCP query tool on my PC, I get this output:

Sending packet:
op=BOOTREQUEST chaddr=74:46:50:03:3E:AA hops=0 xid=C3F84215 secs=0 flags=8000
ciaddr=0.0.0.0 yiaddr=0.0.0.0 siaddr=0.0.0.0 giaddr=0.0.0.0 sname= file=
1 options:
53 (DHCP Message Type): discover
Received packet from 192.168.1.1:67:
op=BOOTREPLY chaddr=74:46:50:03:3E:AA hops=0 xid=C3F84215 secs=0 flags=8000
ciaddr=0.0.0.0 yiaddr=192.168.1.57 siaddr=192.168.1.1 giaddr=0.0.0.0 sname= file=
12 options:
53 (DHCP Message Type): offer
54 (Server Identifier): 192.168.1.1
58 (Renewal (T1) Time Value): 3600 (1 hour)
59 (Rebinding (T2) Time Value): 6300 (1 hour and 45 minutes)
51 (IP Address Lease Time): 7200 (2 hours)
66 (TFTP server name): 192.168.1.6
67 (Bootfile name): pxelinux.1
150 (Unknown): "192.168.1.6" (31 39 32 2E 31 36 38 2E 31 2E 36)
46 (NetBIOS over TCP/IP Node Type Option): hNode
1 (Subnet Mask): 255.255.255.0
3 (Router Option): 192.168.1.1
6 (Domain Name Server Option): 62.24.134.1, 62.24.243.2

So I can see that the 66, 67 and 150 options are working, but the siaddr address is incorrect.

Has anyone else has success with his option?

Cheers

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25 Jan 2021 01:34 #98285 by hornbyp

desdray wrote:
So I type in "192.168.1.6" (no quotes) and hit OK, below. The page refreshes and the value has disappeared from the box.

What is going on? What are valid values for this box?



I have never used this function, but ...

If you type "192.168.1.6" in "SIAddr" and then hit Add, it appears in the "Customized List" at the top :wink:

However ...

If I try it in the simulator @ http://eu.draytek.com:12860/ it doesn't work :!: :?: :!:

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25 Jan 2021 02:10 #98286 by hornbyp
To add ...

On my 2860n, if I add SIAddr as "2.3.4.5" in the GUI, the GUI then lists it as:-
Code:
Enable Interface Option Type Data v LAN1 SIAddr 2.3.4.5


but in the Telnet interface, it shows as:
Code:
> srv dhcp option -l % state idx interface opt type data % enable 1 LAN1 0 SIAddr 0.0.0.0


i.e. the address doesn't appear to be filled in properly (and the option number is zero...) :cry:

At the bottom of this Draytek support article, it says Option 150 = SIAddr ...
https://www.draytek.com/support/knowledge-base/5314

So I tried to add it in the Telnet Interface (the manual doesn't show all the help that SRV DHCP -h shows :roll: )

Code:
> srv dhcp option -e 1 -i 1 -c 150 -a 2.3.4.5


This is accepted, but doesn't actually say "SIAddr" in either the GUI or the telnet - both say "Address" instead :!:

Also, the bug with the actual address remains ... it's still missing from the 'srv dhcp option -l' output. :cry:

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  • desdray
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25 Jan 2021 17:10 #98289 by desdray

hornbyp wrote:

desdray wrote:
So I type in "192.168.1.6" (no quotes) and hit OK, below. The page refreshes and the value has disappeared from the box.

What is going on? What are valid values for this box?



I have never used this function, but ...

If you type "192.168.1.6" in "SIAddr" and then hit Add, it appears in the "Customized List" at the top :wink:

However ...

If I try it in the simulator @ http://eu.draytek.com:12860/ it doesn't work :!: :?: :!:



Doh! how stupidly easy was that.

Typed '192.168.1.6' into 'Next Server...' box and hit add, voila appears as you say.

Now I get :

Received packet from 192.168.1.1:67:
op=BOOTREPLY chaddr=48:5B:39:5A:A4:9A hops=0 xid=3A5AA49A secs=4 flags=8000
ciaddr=0.0.0.0 yiaddr=192.168.1.58 siaddr=192.168.1.6 giaddr=0.0.0.0 sname= file=
12 options:
53 (DHCP Message Type): ack
54 (Server Identifier): 192.168.1.1
58 (Renewal (T1) Time Value): 3600 (1 hour)
59 (Rebinding (T2) Time Value): 6300 (1 hour and 45 minutes)
51 (IP Address Lease Time): 7200 (2 hours)
66 (TFTP server name): 192.168.1.6
67 (Bootfile name): pxelinux.1
150 (Unknown): "192.168.1.6" (31 39 32 2E 31 36 38 2E 31 2E 36)
46 (NetBIOS over TCP/IP Node Type Option): hNode
1 (Subnet Mask): 255.255.255.0
3 (Router Option): 192.168.1.1
6 (Domain Name Server Option): 62.24.134.1, 62.24.243.2

and the PXE boot has jumped into life.

Thanks hornbyp. :D

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26 Jan 2021 00:09 #98291 by hornbyp

desdray wrote:

Now I get :

Received packet from 192.168.1.1:67:
op=BOOTREPLY chaddr=48:5B:39:5A:A4:9A hops=0 xid=3A5AA49A secs=4 flags=8000
ciaddr=0.0.0.0 yiaddr=192.168.1.58 siaddr=192.168.1.6 giaddr=0.0.0.0 sname= file=
12 options:
...



Well that's good :)

It seems I was totally confused about SIAddr anyway ... since it's part of the header, rather than being one of the variable options . I don't think you can set it via the Telnet interface, though you can see that it's configured. (ish!)

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