On Thu, 21 Oct 2021 at 03:04, Geert Stappers via Dnsmasq-discuss < dnsmasq-discuss@lists.thekelleys.org.uk> wrote:
> On Wed, Oct 20, 2021 at 10:56:02PM +0200, Geert Stappers wrote: > > On Wed, Oct 20, 2021 at 02:48:27PM +0530, Shrenik Bhura wrote: > > > On Wed, 20 Oct, 2021, 11:21 Geert Stappers wrote: > > > > On Wed, Oct 20, 2021 at 07:50:58AM +0530, Shrenik Bhura wrote: > > > > > There isn't anything specific in the configuration that serves the > > > > > hostname. I am aware of this feature and when defined it works as > desired. > > > > > But when nothing is explicitly defined to serve hostnames, it is > defaulting > > > > > to 192 as visible in the logs, and only in the case of an RPi. > > > > > When checked on the client with the hostname command, it shows the > full > > > > > hostname - 192.168.67.53 > > > > > > > > Such hostname do I call IPaddress. > > > > > > > > > > > > > The same configuration works fine with a x86 system as no hostname > is being > > > > > served when none is defined. > > Yes, dnsmasq works great. > > > > > > > Have attached the config files involved. > > > > > > > > Make a packet capture and put the .pcap on a server. > > > > Then tell here how to fetch the file. > > > > Next can those who care examine the .pcap with their tool. > > > > (wireshark / tcpdump) > > > > > > > > > Once again, do note that this is the case only for an RPi. So > there is some > > > > > specific logic in dnsmasq coming into play for an RPi that seems > to be > > > > > serving the IP address as the default hostname when none is > present. > > > > > > > > So beside the > > > > /sbin/tcpdump -w rpi.pcap ether host dc:a6:32:78:98:ae > > > > also > > > > /sbin/tcpdump -w worksfine.pcap ether host > MAC_address_of_known_good > > > > > > > > > > Herein is the link to the related packet captures of an RPi and x86 > system > > > - > > > > https://drive.google.com/file/d/11RwpCdbE8W0ohS2QDj4BarZ_VHnEhwfs/view?usp=sharing > > > > > > > The "works fine" is/was captured different as the Raspi capture. > > Luckly is the Raspi packet capture the better one, it contains replies. > > > > What `tshark` says about it. > > Note the packet count and the time offset (columns 1 and 2) > > and that there are three transactions. > > > > > > |$ tshark -nr rpi.pcap | grep DHCP > > | 1 0.000000 0.0.0.0 → 255.255.255.255 DHCP 364 DHCP Discover > - Transaction ID 0x6e9ddeb7 > > | 2 0.001666 192.168.67.1 → 192.168.67.53 DHCP 425 DHCP Offer > - Transaction ID 0x6e9ddeb7 > > | 3 0.059905 0.0.0.0 → 255.255.255.255 DHCP 351 DHCP Request > - Transaction ID 0x6e9ddeb7 > > | 7 0.106212 192.168.67.1 → 192.168.67.53 DHCP 344 DHCP ACK > - Transaction ID 0x6e9ddeb7 > > > |119315 40.665138 0.0.0.0 → 255.255.255.255 DHCP 590 DHCP Discover > - Transaction ID 0x378f8d8b > > |119316 40.668636 192.168.67.1 → 192.168.67.53 DHCP 342 DHCP Offer > - Transaction ID 0x378f8d8b > > |119317 40.673119 0.0.0.0 → 255.255.255.255 DHCP 590 DHCP Request > - Transaction ID 0x378f8d8b > > |119318 40.727456 192.168.67.1 → 192.168.67.53 DHCP 342 DHCP ACK > - Transaction ID 0x378f8d8b > > > |119324 44.861769 0.0.0.0 → 255.255.255.255 DHCP 342 DHCP Discover > - Transaction ID 0x6f84b210 > > |119325 44.866031 192.168.67.1 → 192.168.67.53 DHCP 342 DHCP Offer > - Transaction ID 0x6f84b210 > > |119326 44.866612 0.0.0.0 → 255.255.255.255 DHCP 342 DHCP Request > - Transaction ID 0x6f84b210 > > |119327 44.911006 192.168.67.1 → 192.168.67.53 DHCP 343 DHCP ACK > - Transaction ID 0x6f84b210 > > |$ > > > > > > Tcpdump Verbose, `-v`, of that: > > > > $ tcpdump -nr rpi.pcap -v port bootpc > > reading from file rpi.pcap, link-type EN10MB (Ethernet), snapshot length > 262144 > > 10:48:00.072173 IP (tos 0x0, ttl 64, id 20588, offset 0, flags [none], > proto UDP (17), length 350) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 322, xid 0x6e9ddeb7, Flags [none] > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Discover > > DHCP Discover > > > Parameter-Request (55), length 14: > > Subnet-Mask (1), Default-Gateway (3), Vendor-Option (43), > Vendor-Class (60) > > TFTP (66), BF (67), Unknown (128), Unknown (129) > > Unknown (130), Unknown (131), Unknown (132), Unknown (133) > > Unknown (134), Unknown (135) > > Vendor-Class (60), length 32: > "PXEClient:Arch:00000:UNDI:002001" > > ARCH (93), length 2: 0 > > And ARCH 0 is "PC" ... > > > > NDI (94), length 3: 1.2.1 > > GUID (97), length 17: > 0.82.80.105.52.18.49.192.0.50.120.152.174.94.119.158.94 > > 10:48:00.073839 IP (tos 0xc0, ttl 64, id 5852, offset 0, flags [none], > proto UDP (17), length 411) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 383, > xid 0x6e9ddeb7, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Offer > > DHCP Offer > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > BF (67), length 19: "ltsp/undionly.kpxe^@" > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > Vendor-Class (60), length 9: "PXEClient" > > GUID (97), length 17: > 0.82.80.105.52.18.49.192.0.50.120.152.174.94.119.158.94 > > Vendor-Option (43), length 44: > 6.1.3.10.4.0.80.88.69.8.7.128.4.1.192.168.67.1.9.23.128.4.20.82.97.115.112.98.101.114.114.121.32.80.105.32.66.111.111.116.32.32.32.255 > > 10:48:00.132078 IP (tos 0x0, ttl 64, id 20590, offset 0, flags [none], > proto UDP (17), length 337) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 309, xid 0x6e9ddeb7, Flags [none] > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Request > > DHCP Request > > > > Requested-IP (50), length 4: 192.168.67.53 > > Server-ID (54), length 4: 192.168.67.1 > > Vendor-Class (60), length 32: > "PXEClient:Arch:00000:UNDI:002001" > > GUID (97), length 17: > 0.82.80.105.52.18.49.192.0.50.120.152.174.94.119.158.94 > > 10:48:00.178385 IP (tos 0xc0, ttl 64, id 5869, offset 0, flags [none], > proto UDP (17), length 330) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 302, > xid 0x6e9ddeb7, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: ACK > > DHCP Acknowledge > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > LOG (7), length 4: 192.168.67.1 > > Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 > > First "DHCP Cycle" is complete. > Next DHCP Cycle starts. > > > 10:48:40.737311 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto > UDP (17), length 576) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 548, xid 0x378f8d8b, Flags [none] > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Discover > > DHCP Discover > > > > Parameter-Request (55), length 9: > > Subnet-Mask (1), Default-Gateway (3), Domain-Name-Server > (6), Hostname (12) > > Domain-Name (15), RP (17), MTU (26), YD (40) > > NTP (42) > > 10:48:40.740809 IP (tos 0xc0, ttl 64, id 3785, offset 0, flags [none], > proto UDP (17), length 328) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 300, > xid 0x378f8d8b, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Offer > > DHCP Offer > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 > > 10:48:40.745292 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto > UDP (17), length 576) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 548, xid 0x378f8d8b, Flags [none] > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Request > > DHCP Request > > > > Server-ID (54), length 4: 192.168.67.1 > > Requested-IP (50), length 4: 192.168.67.53 > > Parameter-Request (55), length 9: > > Subnet-Mask (1), Default-Gateway (3), Domain-Name-Server > (6), Hostname (12) > > Domain-Name (15), RP (17), MTU (26), YD (40) > > NTP (42) > > 10:48:40.799629 IP (tos 0xc0, ttl 64, id 3788, offset 0, flags [none], > proto UDP (17), length 328) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 300, > xid 0x378f8d8b, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: ACK > > DHCP Acknowledge > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 > > Second "DHCP Cycle" is complete. > > |119318 40.727456 192.168.67.1 → 192.168.67.53 DHCP 342 DHCP ACK > - Transaction ID 0x378f8d8b > > > } Five ICMPv6 packets > > > |119324 44.861769 0.0.0.0 → 255.255.255.255 DHCP 342 DHCP Discover > - Transaction ID 0x6f84b210 > Next DHCP Cycle starts. > > > 10:48:44.933942 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], > proto UDP (17), length 328) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 300, xid 0x6f84b210, Flags [none] > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Discover > > DHCP Discover > > > > Hostname (12), length 13: "192.168.67.53" > > Client says "My hostname is '192.168.67.53'" > > > Parameter-Request (55), length 13: > > Subnet-Mask (1), BR (28), Time-Zone (2), Default-Gateway (3) > > Domain-Name (15), Domain-Name-Server (6), Unknown (119), > Hostname (12) > > Netbios-Name-Server (44), Netbios-Scope (47), MTU (26), > Classless-Static-Route (121) > > NTP (42) > > 10:48:44.938204 IP (tos 0xc0, ttl 64, id 3933, offset 0, flags [none], > proto UDP (17), length 328) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 300, > xid 0x6f84b210, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Offer > > DHCP Offer > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 > > 10:48:44.938785 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], > proto UDP (17), length 328) > > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > dc:a6:32:78:98:ae, length 300, xid 0x6f84b210, Flags [none] > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: Request > > DHCP Request > > > > Server-ID (54), length 4: 192.168.67.1 > > Requested-IP (50), length 4: 192.168.67.53 > > Hostname (12), length 13: "192.168.67.53" > > Client says "My hostname is '192.168.67.53'" > > > Parameter-Request (55), length 13: > > Subnet-Mask (1), BR (28), Time-Zone (2), Default-Gateway (3) > > Domain-Name (15), Domain-Name-Server (6), Unknown (119), > Hostname (12) > > Netbios-Name-Server (44), Netbios-Scope (47), MTU (26), > Classless-Static-Route (121) > > NTP (42) > > 10:48:44.983179 IP (tos 0xc0, ttl 64, id 3934, offset 0, flags [none], > proto UDP (17), length 329) > > 192.168.67.1.67 > 192.168.67.53.68: BOOTP/DHCP, Reply, length 301, > xid 0x6f84b210, Flags [none] > > Your-IP 192.168.67.53 > > Server-IP 192.168.67.1 > > Client-Ethernet-Address dc:a6:32:78:98:ae > > Vendor-rfc1048 Extensions > > Magic Cookie 0x63825363 > > DHCP-Message (53), length 1: ACK > > DHCP Acknowledge > > > > Server-ID (54), length 4: 192.168.67.1 > > Lease-Time (51), length 4: 43200 > > RN (58), length 4: 21600 > > RB (59), length 4: 37800 > > Subnet-Mask (1), length 4: 255.255.255.0 > > BR (28), length 4: 192.168.67.255 > > Default-Gateway (3), length 4: 192.168.67.1 > > Hostname (12), length 3: "192" > > Server says "Your hostname is '192'" > May be the code that logs this line needs to be checked if it is just printing part of the complete hostname i.e. IP address. > > Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 > > > > > > More in the next message. > > Done "in line" > > > Back to: > > > > On Wed, Oct 20, 2021 at 07:50:58AM +0530, Shrenik Bhura wrote: > > > > > There isn't anything specific in the configuration that serves the > > > > > hostname. I am aware of this feature and when defined it works as > desired. > > Acknowledge on "it works as desired". > > > > > > > But when nothing is explicitly defined to serve hostnames, > > > > > it is defaulting to 192 as visible in the logs, > > There I tent to disagree. > > > > > > > and only in the case of an RPi. > > I do read that as > "There are some more factors. There are yet unknown factors." > Nothing more to be shared from my end. With the inputs that I have shared, anyone in possession of a RPi 4B or RPi 400 should be able to reproduce this. > > > > > > When checked on the client with the hostname command, > > > > > it shows the full hostname - 192.168.67.53 > > Yes. And the question is: How did it get there? > > I have no clue. I have just reported the facts and nothing more, nothing less. :) You guys are the experts. Groeten > Geert Stappers > > Regards Shrenik
_______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss
