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: > > > > > > Hi Dominik, > > > > Hello Archive visitor, > > Hello Mailinglist subscriber, > > > > > > > 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. > > > > > > Also it would be ideal to improve the logs as well to reflect the full > > > hostname, if at all. > > > > > > 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. |$ tcpdump -r worksfine.pcap port bootpc |reading from file worksfine.pcap, link-type EN10MB (Ethernet), snapshot length 262144 |10:52:34.037140 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 347 |10:52:37.200771 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 359 |10:52:40.846979 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 385 |10:52:43.077918 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 385 |10:52:47.087553 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 397 |10:52:59.920696 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 300 |10:52:59.922192 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from f4:4d:30:63:75:82 (oui Unknown), length 300 |$ tcpdump -r rpi.pcap port bootpc |reading from file rpi.pcap, link-type EN10MB (Ethernet), snapshot length 262144 |10:48:00.072173 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 322 |10:48:00.073839 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 383 |10:48:00.132078 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 309 |10:48:00.178385 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 302 |10:48:40.737311 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 548 |10:48:40.740809 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 300 |10:48:40.745292 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 548 |10:48:40.799629 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 300 |10:48:44.933942 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 300 |10:48:44.938204 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 300 |10:48:44.938785 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from dc:a6:32:78:98:ae (oui Unknown), length 300 |10:48:44.983179 IP 192.168.67.1.bootps > 192.168.67.53.bootpc: BOOTP/DHCP, Reply, length 301 |$ 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 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 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 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 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 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 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 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 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 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 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 10:48:44.933942 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 Hostname (12), length 13: "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 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 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" 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 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" Domain-Name-Server (6), length 8: 8.8.8.8,8.8.8.8 More in the next message. Groeten Geert Stappers -- Silence is hard to parse _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss