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Bootstrap Protocol (offer) [closed]

asked 2018-08-14 06:04:30 +0000

aussupport gravatar image

HI all,

I can see Option 150 with unknown TFTP Servers? But in DHCP Option 150 is set to myserver.domain.com

Bootstrap

As

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Closed for the following reason duplicate question by aussupport
close date 2018-08-15 09:59:27.696364

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answered 2018-08-14 06:23:07 +0000

updated 2018-08-14 06:26:23 +0000

RFC5859 states that DHCP option 150 must contain IPv4 address, not domain name. Please check your DHCP server configuration.

And also check your DHCP option 66 (TFTP Server Name option) which is present in the offer.

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I couldn't find any of these IP's?

TFTP

Not in DHCP? As

aussupport gravatar imageaussupport ( 2018-08-14 11:12:26 +0000 )edit

Could you please be more specific in your question? Can't find these IP where exactly? In your network? Can't use them? In DHCP server configuration?

Keep in mind you're not communicating with DHCP server directly, DHCP relay agent is in use. Non-zero Relay agent IP address indicates it. An IP of actual DHCP server is in DHCP server identifier option 54. Spot this IP, look at actual DHCP server configuration and you'll find these IP addresses there.

Packet_vlad gravatar imagePacket_vlad ( 2018-08-14 13:06:33 +0000 )edit

Hi,

You can see these IP's in that image on TFTP Link.

Option: (150) TFTP Server Address TFTP Server Address: 99.105.99.52 TFTP Server Address: 45.112.114.111 TFTP Server Address: 100.46.115.101 TFTP Server Address: 114.99.111.98 TFTP Server Address: 112.111.46.99 TFTP Server Address: 111.109.46.97 [Expert Info (Error/Protocol): Option length isn't a multiple of 4]

Option: (54) DHCP Server Identifier DHCP Server Identifier: 10.1.171.1

In DHCP Server

Option 150 is set for myserver.domain.com

As

aussupport gravatar imageaussupport ( 2018-08-15 01:04:20 +0000 )edit

What you see is the IP address interpretation of the text "myserver.domain.com". If you fill in text "myserver.domain.com" the ASCII character values are interpreted as IP addresses by Wireshark, since that is the required format. I bet the real domain name you typed in started with "cic4-prod".

Jaap gravatar imageJaap ( 2018-08-15 05:01:42 +0000 )edit

Thanks for your help.

aussupport gravatar imageaussupport ( 2018-08-15 09:58:55 +0000 )edit

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Asked: 2018-08-14 06:04:30 +0000

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Last updated: Aug 15