Description of problem: Dhcp-client(isc-dhclient-4.4.2b1) packaged with RHEL 9.2 is not compatible with windows server 2019 acting as a dhcpv6 server.dhcp-client is unable to process DHCPv6 advertise packet coming from Dhcpv6 server. dhcp-client works fine with the dhcpv6 server running in any linux VM(VYOS,ubuntu). Version-Release number of selected component (if applicable): dhcp-client : isc-dhclient-4.4.2b1 How reproducible: Always reproducible Steps to Reproduce: 1.Install dhcp-client package in RHEL 9.2 2.run dhclient6 with command "dhclient -6 -v <intf_name>".interface from client server are back to back connected.start the dhcpv6 server on windows server VM (2019). 3.Capture ipv6 packets either in client or in server . Actual results: from the packet captures and verbose logs from client, we are observing that server is sending dhcpv6 advertise packet but somehow client is not able to process it and send dhcpv6 request packet . Expected results: Verbose logs from dhclient should show the processing of dhcpv6 advertise packet from dhcpv6 server and client should send dhcpv6 request packet to server. Additional info:Issue is there in centos8/rockylinux 9/RHEL 8/RHEL 9.2 linux versions. dhclient packaged in ubuntu linux distribution is working as expected.There might be a good chance that ubuntu/debian community has applied patches on top of isc-dhcp-client package.
Thank you for reporting this issue. Please, due to the fact, I don't have access to windows server machine right now, could you provide the following details to help me debug this issue further? Q1. What is the version of Ubuntu and dhcp package you did the test with? Q2. Would you be able to share dhclient verbose output from both RHEL and Ubuntu? Q3. Could you also share from both RHEL and Ubuntu dhclient-*.log output of the below commands? RHEL# strace -qfTttvys 4096 -o /tmp/dhclient-rhel.log dhclient -d -6 -v <intf_name> Ubuntu# strace -qfTttvys 4096 -o /tmp/dhclient-ubuntu.log dhclient -d -6 -v <intf_name> Thank you!
Hi Martin, Thanks for looking into this.My answers are below: A1: ubuntu version (20.4.6 LTS) and dhclient package is 4.4.1. ubuntu@ubuntu17-ise-Server:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 20.04.6 LTS Release: 20.04 Codename: focal ubuntu@ubuntu17-ise-Server:~$ dhclient --version isc-dhclient-4.4.1 A2: Yes i have collected the verbose output of both RHEL and ubuntu machines. //////////////////////////////////////////////////////////verbose output from ubuntu VM (20.4)////////////////////////////////////////////////////// ubuntu@ubuntu17-ise-Server:~$ sudo dhclient -6 -v ens224 Internet Systems Consortium DHCP Client 4.4.1 Copyright 2004-2018 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on Socket/ens224 Sending on Socket/ens224 PRC: Soliciting for leases (INIT). XMT: Forming Solicit, 0 ms elapsed. XMT: X-- IA_NA 29:c9:18:88 XMT: | X-- Request renew in +3600 XMT: | X-- Request rebind in +5400 XMT: | X-- Request address 2019:2018::a74c:d480:e68a:c78b. XMT: | | X-- Request preferred in +7200 XMT: | | X-- Request valid in +10800 XMT: Solicit on ens224, interval 1050ms. RCV: Advertise message on ens224 from 2019:2018::1. RCV: X-- Preference 1. RCV: X-- IA_NA 29:c9:18:88 RCV: | X-- starts 1687503592 RCV: | X-- t1 - renew +900 RCV: | X-- t2 - rebind +1440 RCV: | X-- [Options] RCV: | | X-- IAADDR 2019:2018::a74c:d480:e68a:c78b RCV: | | | X-- Preferred lifetime 1800. RCV: | | | X-- Max lifetime 1800. RCV: X-- Server ID: 00:01:00:00:63:17:2d:a3:00:0c:29:e0:86:97 RCV: Advertisement recorded. PRC: Selecting best advertised lease. PRC: Considering best lease. PRC: X-- Initial candidate 00:01:00:00:63:17:2d:a3:00:0c:29:e0:86:97 (s: 10104, p: 1). XMT: Forming Request, 0 ms elapsed. XMT: X-- IA_NA 29:c9:18:88 XMT: | X-- Requested renew +3600 XMT: | X-- Requested rebind +5400 XMT: | | X-- IAADDR 2019:2018::a74c:d480:e68a:c78b XMT: | | | X-- Preferred lifetime +7200 XMT: | | | X-- Max lifetime +7500 XMT: V IA_NA appended. XMT: Request on ens224, interval 1000ms. RCV: Reply message on ens224 from 2019:2018::1. RCV: X-- IA_NA 29:c9:18:88 RCV: | X-- starts 1687503593 RCV: | X-- t1 - renew +900 RCV: | X-- t2 - rebind +1440 RCV: | X-- [Options] RCV: | | X-- IAADDR 2019:2018::a74c:d480:e68a:c78b RCV: | | | X-- Preferred lifetime 1800. RCV: | | | X-- Max lifetime 1800. RCV: X-- Server ID: 00:01:00:00:63:17:2d:a3:00:0c:29:e0:86:97 PRC: Bound to lease 00:01:00:00:63:17:2d:a3:00:0c:29:e0:86:97. //////////////////////////////////////////////////////verbose message of dhclient package from RHEL 9.2//////////////////////////////////////////////// [root@localhost ~]# dhclient -6 -v ens224 Internet Systems Consortium DHCP Client 4.4.2b1 Copyright 2004-2019 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ grep: /etc/sysconfig/network-scripts/ifcfg-*: No such file or directory grep: /etc/sysconfig/network-scripts/ifcfg-*: No such file or directory grep: /etc/sysconfig/network-scripts/ifcfg-*: No such file or directory Listening on Socket/ens224 Sending on Socket/ens224 PRC: Soliciting for leases (INIT). XMT: Forming Solicit, 0 ms elapsed. XMT: X-- IA_NA 56:83:ca:d3 XMT: | X-- Request renew in +3600 XMT: | X-- Request rebind in +5400 XMT: Solicit on ens224, interval 1090ms. XMT: Forming Solicit, 1090 ms elapsed. XMT: X-- IA_NA 56:83:ca:d3 XMT: | X-- Request renew in +3600 XMT: | X-- Request rebind in +5400 XMT: Solicit on ens224, interval 2170ms. XMT: Forming Solicit, 3260 ms elapsed. XMT: X-- IA_NA 56:83:ca:d3 XMT: | X-- Request renew in +3600 XMT: | X-- Request rebind in +5400 XMT: Solicit on ens224, interval 4190ms. XMT: Forming Solicit, 7450 ms elapsed. XMT: X-- IA_NA 56:83:ca:d3 XMT: | X-- Request renew in +3600 XMT: | X-- Request rebind in +5400 XMT: Solicit on ens224, interval 8060ms. A3. strace logs from both the machines RHEL and ubuntu are attached as attachments. RHEL 9.2 : dhclient-rhel.log Ubuntu 20.04: dhclient-ubuntu.log NOTE: based on my debugging so far what is observed is that dhclient is somehow silently dropping the dhcpv6 advertise packet coming from windows dhcpv6 server. @martin we can use free version of windows 2019 server iso and spawn dhcpv6 server in it.Please refer this link https://archive.org/details/en_windows_server_2019_x64_dvd_4cb967d8_202209
Created attachment 1972200 [details] strace logs from rhel 9.2.
Created attachment 1972201 [details] strace logs from ubuntu 20.04
Hi Martin, Do you need any other information? Regards, Rahul
Hi Martin, Could you please update the latest on this issue? Regards, rahul
Hi @mosvald, Could you please help? Regards, rahul