[Ltsp-discuss] Help interpreting tcpdump -v output

[Brian Caine]

Title: Help interpreting tcpdump -v output

To preface this let me say that I am extremely new to linux.  I have aspirations of setting up a LTSP lab in my classroom, but first need to demonstrate to the powers that be that it would be functional and beneficial.  

To test a setup, I had to work with a pieced together server of the best components I had laying around, in an attempt to boot a single terminal. (specs: 600Mhz celeron processor 256MB ram 80Gig HD) 

I am able to assign the IP to the client.  However the tftp process is very slow (this appears to be the slowest process on actually capable servers, so I expected that.  I was quite doubtful that the server was up to the job, but am hoping for confirmation from someone more experienced.  The dots appear quite slowly when attempting to load the vmlinuz file, and I have placed the results of a tcpdump below.  BTW the longest I have allowed is about 3hours for the file to loads. :)

Sorry for the long file and thanks for any input ahead of time.
Brian 

[EMAIL PROTECTED]:~$ sudo tcpdump -v
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
13:03:25.359207 IP (tos 0x0, ttl  60, id 0, offset 0, flags [none], length: 576) 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:08:a1:7c:4f:06, length: 548, xid:0xa18665cf, flags: [none]
          Client Ethernet Address: 00:08:a1:7c:4f:06 [|bootp]
13:03:25.400357 IP (tos 0x10, ttl  64, id 0, offset 0, flags [none], length: 328) 192.168.0.254.bootps > ws001.ltsp.bootpc: BOOTP/DHCP, Reply, length: 300, xid:0xa18665cf, flags: [none]
          Your IP: ws001.ltsp
          Server IP: 192.168.0.254
          Client Ethernet Address: 00:08:a1:7c:4f:06 [|bootp]
13:03:25.400821 IP (tos 0x0, ttl  60, id 0, offset 0, flags [none], length: 576) ws001.ltsp.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:08:a1:7c:4f:06, length: 548, xid:0xa18665cf, flags: [none]
          Client Ethernet Address: 00:08:a1:7c:4f:06 [|bootp]
13:03:25.401652 IP (tos 0x10, ttl  64, id 0, offset 0, flags [none], length: 333) 192.168.0.254.bootps > ws001.ltsp.bootpc: BOOTP/DHCP, Reply, length: 305, xid:0xa18665cf, flags: [none]
          Your IP: ws001.ltsp
          Server IP: 192.168.0.254
          Client Ethernet Address: 00:08:a1:7c:4f:06 [|bootp]


Cleint Mapping of ip to hw addr - comment by bcaine
13:03:25.403440 arp who-has 192.168.0.254 tell ws001.ltsp
13:03:25.403612 arp reply 192.168.0.254 is-at 00:08:a1:7c:50:e7

Here is where the tftp starts, and each of these entries corresponds to one dot filling the screen. There were more entries of the same (one per dot) when tcpdump -vv was run.

13:03:25.403706 IP (tos 0x0, ttl  60, id 0, offset 0, flags [none], length: 76) ws001.ltsp.2001 > 192.168.0.254.tftp: [udp sum ok]  48 RRQ "/lts/vmlinuz-2.4.26-ltsp-2" octet blksize 1432
13:03:35.952881 IP (tos 0x0, ttl  60, id 0, offset 0, flags [none], length: 76) ws001.ltsp.2002 > 192.168.0.254.tftp: [udp sum ok]  48 RRQ "/lts/vmlinuz-2.4.26-ltsp-2" octet blksize 1432
13:03:56.492997 IP (tos 0x0, ttl  60, id 0, offset 0, flags [none], length: 76) ws001.ltsp.2003 > 192.168.0.254.tftp: [udp sum ok]  48 RRQ "/lts/vmlinuz-2.4.26-ltsp-2" octet blksize 1432

9 packets captured
9 packets received by filter
0 packets dropped by kernel