[syslinux] pxelinux tries to load ldlinux.c32 from DHCP server, instead of next-server

Gene Cumm gene.cumm at gmail.com
Fri Sep 11 19:58:07 PDT 2015


On Fri, Sep 11, 2015 at 5:24 PM, Teun Docter via Syslinux
<syslinux at zytor.com> wrote:
> Hello list,
>
> We have a scenario where our TFTP server is not the same IP as our DHCP
> server. While testing with 6.03, our setup works just fine.
>
> However with the master branch, for some reason pxelinux.0 is fetched from
> the TFTP servers IP, but then it tries to load ldlinux.c32 from the DHCP
> servers IP.

That seems like a regressive interaction.

> I've tracked down this problem to the following commit:
>
> 8e53b8a63c8ae1e266f63f502a537b9e8e03baed core/pxe: Don't prevent serverip
> override
>
> If I reverse that change on the current master everything is working fine.
> This was with tested against 26d37f75aff50879795692728dbeb8ca57a8a226.
>
> We're not using uefi for this test. (The machine is actually a KVM instance
> in OpenStack.)

Always good to note.  Thanks.

> I've captured the following DHCP ACK:
>
> 10.141.20.1.bootps > 10.141.20.2.bootpc: [udp sum ok] BOOTP/DHCP, Reply,
> length 399, xid 0xf0eb955a, secs 14, Flags [none] (0x0000)
>           Your-IP 10.141.20.2
>           Server-IP 10.141.255.254
>           Client-Ethernet-Address fa:16:3e:08:31:b9
>           Vendor-rfc1048 Extensions
>             Magic Cookie 0x63825363
>             DHCP-Message Option 53, length 1: ACK
>             Server-ID Option 54, length 4: 10.141.20.1
>             Lease-Time Option 51, length 4: 86400
>             RN Option 58, length 4: 43200
>             RB Option 59, length 4: 75600
>             TFTP Option 66, length 7: "master^@"

What does the name "master.openstacklocal" point to?  I typically set
dhcp-66 to the dotted quad string of the destination TFTP.

>             BF Option 67, length 11: "pxelinux.0^@"
>             Subnet-Mask Option 1, length 4: 255.255.0.0
>             BR Option 28, length 4: 10.141.255.255
>             Domain-Name-Server Option 6, length 4: 10.141.20.1
>             Domain-Name Option 15, length 14: "openstacklocal"
>             Hostname Option 12, length 16: "host-10-141-20-2"
>             Default-Gateway Option 3, length 4: 10.141.255.250
>             T209 Option 209, length 45:
> 112.120.101.108.105.110.117.120.46.99.102.103.47.99.97.116.101.103.111.114.121.46.118.105.114.116.117.97.108.45.110.111.100.101.115.46.111.112.101.110.115.116.
> 97.99.107
>             MTU Option 26, length 2: 1450
>             END Option 255, length 0
>
> Followed by this TFTP request:
>
> 10.141.20.2.49152 > 10.141.20.1.tftp: [udp sum ok]  41 RRQ "ldlinux.c32"
> octet tsize 0 blksize 1408
>
> It should be sending that TFTP request to 10.141.255.254.

Depends on what master points at.  Otherwise, it sounds like a broken
interaction.

> So now I'm wondering, could this be a bug? Or should we change something in
> our DHCP settings? Is any further info required?
>
> As a side note, could this be related to the recent thread with the
> following subject: "BUG: confusion between next-server and gateway"?
> (http://www.syslinux.org/archives/2015-September/024090.html)

-- 
-Gene


More information about the Syslinux mailing list