On Tue, Oct 20, 2020 at 09:25:01PM +0200, Daniele Riccucci wrote: > Hello, > I'm trying to push a different DNS server via DHCP to a specific client (a > VoIP thingie from Grandstream, model HT802) from an EdgeRouter; the current > firmware is running Dnsmasq version 2.79-1-2-geff17ee. > > Some options are already generated by the OS unfortunately, namely: > > dhcp-range=set:home,10.0.0.20,10.0.0.254,255.255.255.0,86400 > domain=home.domain.com,10.0.0.0/24,local > dhcp-option=tag:home,option:domain-name,home.domain.com > dhcp-option=tag:home,option:router,10.0.0.1 > dhcp-option=tag:home,option:dns-server,10.0.0.1 > dhcp-host=c0:74:ad:0c:0c:b7,set:home,10.0.0.5 > host-record=voipgw.home.domain.com,10.0.0.5,86400 > > which are contained in /etc/dnsmasq.d/dnsmasq-dhcp-config.conf. > I can only set options above this point (/etc/dnsmasq.conf), and I tried > with: > > dhcp-option=tag:home,option:dns-server,10.0.0.1 > options dhcp-option=vendor:HT8XX,option:dns-server,85.38.28.0,85.38.28.1 > options > dhcp-option-force=vendor:HT8XX,option:dns-server,85.38.28.0,85.38.28.1 > > because from tcpdump I saw that the client was sending a Vendor-Class > string: > > c0:74:ad:0c:0c:b7 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 590: > (tos 0x0, ttl 64, id 0, offset 0, flags [none], proto UDP (17), length 576) > 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from > c0:74:ad:0c:0c:b7, length 548, xid 0xbed7bb5e, Flags [none] > Client-Ethernet-Address c0:74:ad:0c:0c:b7 > Vendor-rfc1048 Extensions > Magic Cookie 0x63825363 > DHCP-Message Option 53, length 1: Discover > Client-ID Option 61, length 7: ether c0:74:ad:0c:0c:b7 > Hostname Option 12, length 6: "voipgw" > Vendor-Class Option 60, length 18: "HT8XX dslforum.org" > Parameter-Request Option 55, length 17: > Subnet-Mask, Time-Zone, Default-Gateway, Domain-Name-Server > Hostname, Domain-Name, TTL, BR > Static-Route, NTP, Vendor-Option, Lease-Time > Server-ID, TFTP, Classless-Static-Route, Option 125 > Option 160 > > However, the reply from dnsmasq is sending 10.0.0.1 as DNS server: > > 20:19:01.081957 24:a4:3c:b3:c2:8d > c0:74:ad:0c:0c:b7, ethertype IPv4 > (0x0800), length 390: (tos 0xc0, ttl 64, id 53937, offset 0, flags [none], > proto UDP (17), length 376) > 10.0.0.1.67 > 10.0.0.5.68: BOOTP/DHCP, Reply, length 348, xid > 0xbed7bb5e, Flags [none] > Client-IP 10.0.0.5 > Server-IP 10.0.0.1 > Client-Ethernet-Address c0:74:ad:0c:0c:b7 > Vendor-rfc1048 Extensions > Magic Cookie 0x63825363 > DHCP-Message Option 53, length 1: ACK > Server-ID Option 54, length 4: 10.0.0.1 > Lease-Time Option 51, length 4: 86358 > Subnet-Mask Option 1, length 4: 255.255.255.0 > BR Option 28, length 4: 10.0.0.255 > Hostname Option 12, length 6: "voipgw" > Domain-Name-Server Option 6, length 4: 10.0.0.1
Option 6 > Default-Gateway Option 3, length 4: 10.0.0.1 > Domain-Name Option 15, length 15: "home.domain.com" > Vendor-Option Option 43, length 21: > 6.8.85.38.28.0.85.38.28.1. Option 6, eight bytes, dns.ser.ver.0, dns.ser.ver.1 >\ 6.8.85.38.28.0.85.38.28.1.255 Option 6, eight bytes, dns.ser.ver.0, dns.ser.ver.1, end > Vendor-Class Option 60, length 18: "HT8XX dslforum.org" > > Also shown from the device: > > Product Model: HT802 > MAC Address: c0:74:ad:0c:0c:b7 > Network: > IPv4 Address -- 10.0.0.5 > IPv6 Address -- > Netmask -- 255.255.255.0 > Gateway -- 10.0.0.1 > DNS Server -- 10.0.0.1 > > How could I solve this? Is there a way to override the dns-server option for > this device? Something like changing the | dhcp-host=c0:74:ad:0c:0c:b7,set:home,10.0.0.5 | host-record=voipgw.home.domain.com,10.0.0.5,86400 in | dhcp-host=c0:74:ad:0c:0c:b7,set:myvoiptag,10.0.0.5,voipgw | dhcp-option=tag:myvoiptag,option:dns-server,85.38.28.1 > I can send further tcpdumps if required. > Thank you. Please provide feedback. Regards Geert Stappers -- Silence is hard to parse _______________________________________________ Dnsmasq-discuss mailing list [email protected] http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
