☰

dhcpcd dhcpv6 在路由器通告後逾時，從不傳送 DHCPv6 請求

tag-icon • tag-icon dhcp ipv6 netctl dhcpcd
dhcpcd dhcpv6 在路由器通告後逾時，從不傳送 DHCPv6 請求

我使用 Linux 主機作為 IPv4 路由器，並研究啟用 IPv6（有人告訴我，這是未來）。我已經使用dhcpcddhcpv4 客戶端從 ISP 取得位址，所以我想我也可以將它用於 dhcpv6。

不幸的是，雖然我可以看到dhcpcd發送請求訊息並且可以看到 dhcpv6 伺服器回應 2x dhcpv6 廣告訊息，但我沒有看到dhcpcd發送 dhcpv6 請求。

我看到以下三個訊息序列重複 3 次，然後dhcpcd超時：

15:41:06.457440 IP6 (flowlabel 0x1e0d7, hlim 1, next-header UDP (17) payload length: 152) fe80::aaaa:aaaa:aaaa:aaaa.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp sum ok] dhcp6 solicit (xid=bc3d12 (client-ID type 4) (elapsed-time 0) (vendor-class) (rapid-commit) (IA_NA IAID:403318227 T1:0 T2:0) (Client-FQDN) (reconfigure-accept) (option-request DNS-server DNS-search-list Client-FQDN opt_82 opt_83))

15:41:07.168805 IP6 (class 0x48, hlim 56, next-header UDP (17) payload length: 140) 2001:558:4082:7f::1.dhcpv6-server > fe80::aaaa:aaaa:aaaa:aaaa.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=bc3d12 (client-ID type 4) (server-ID hwaddr/time type 1 time 493924036 40a8f0347664) (IA_NA IAID:403318227 T1:1800 T2:2880 (IA_ADDR 2001:558:600a:7f:bbbb:bbbb:bbbb:bbbb pltime:3600 vltime:3600)) (reconfigure-accept) (DNS-server cdns01.comcast.net cdns02.comcast.net) (Client-FQDN))

15:41:07.168912 IP6 (class 0x48, hlim 56, next-header UDP (17) payload length: 140) 2001:558:4082:7f::1.dhcpv6-server > fe80::aaaa:aaaa:aaaa:aaaa.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=bc3d12 (client-ID type 4) (server-ID hwaddr/time type 1 time 493924036 40a8f0347664) (IA_NA IAID:403318227 T1:1800 T2:2880 (IA_ADDR 2001:558:600a:7f:bbbb:bbbb:bbbb:bbbb pltime:3600 vltime:3600)) (reconfigure-accept) (DNS-server cdns01.comcast.net cdns02.comcast.net) (Client-FQDN))


Mar 14 15:41:05 router dhcpcd[126860]: DUID ...
Mar 14 15:41:05 router dhcpcd[126860]: enp8s0: IAID 18:0a:25:d3
Mar 14 15:41:05 router dhcpcd[126860]: enp8s0: adding address fe80::aaaa:aaaa:aaaa:aaaa
Mar 14 15:41:05 router dhcpcd[126860]: enp8s0: soliciting an IPv6 router
Mar 14 15:41:06 router dhcpcd[126860]: enp8s0: Router Advertisement from fe80::2aa:bbff:fecc:102
Mar 14 15:41:06 router dhcpcd[126860]: enp8s0: no global addresses for default route
Mar 14 15:41:06 router dhcpcd[126860]: enp8s0: soliciting a DHCPv6 lease
Mar 14 15:41:35 router dhcpcd[126860]: timed out
Mar 14 15:41:35 router dhcpcd[126860]: dhcpcd exited

$ cat /proc/sys/net/ipv6/conf/enp8s0/autoconf
1
$ cat /proc/sys/net/ipv6/conf/enp8s0/accept_ra_pinfo
1
$ cat /proc/sys/net/ipv6/conf/enp8s0/forwarding 
0
$ cat /proc/sys/net/ipv6/conf/enp8s0/accept_ra
0

我的近期目標是讓 IPv6 在此「路由器」主機上工作，而不進行前綴委派或任何實際的 IPv6 路由，因此目前forwarding設定為。0當該主機作為 IPv6 用戶端工作後，我將處理路由問題。

我嘗試過設置accept_ra為2，但dhcpcd將其設置回0。

netctl我透過以下非常基本的設定檔呼叫 dhcpcd 。確切的呼叫是dhcpcd -6 -q -t 30 enp8s0：

$ cat /etc/netctl/enp8s0 
Interface=enp8s0
Connection=ethernet
IP=dhcp
DHCPClient=dhcpcd
IP6=dhcp
DHCP6Client=dhcpcd

$ dhcpcd --version
dhcpcd 8.1.6
Copyright (c) 2006-2019 Roy Marples
Compiled in features: INET ARP ARPing IPv4LL INET6 DHCPv6 AUTH

$ cat /etc/dhcpcd.conf  | egrep -v '^#'


hostname

duid

persistent

option rapid_commit

option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
option interface_mtu


require dhcp_server_identifier

slaac private
noipv4ll

答案1

康卡斯特似乎錯誤地截斷了其在廣告訊息中發送的客戶端 ID。我dhcpcd使用以下-d選項手動調用：

Mar 14 16:22:35 router dhcpcd[127923]: enp8s0: broadcasting SOLICIT6 (xid 0xc32482), next in 0.9 seconds
Mar 14 16:22:35 router dhcpcd[127923]: enp8s0: incorrect client ID from 2001:558:4082:7f::1
Mar 14 16:22:35 router dhcpcd[127923]: enp8s0: incorrect client ID from 2001:558:4082:7f::1

使用wireshark我觀察了客戶端ID：

11  5.308301    fe80::aaaa:aaaa:aaaa:aaaa   ff02::1:2   DHCPv6  208 Solicit XID: 0xc32482 CID: 000403000200040005000006000700080009 
12  5.360355    2001:558:4082:7f::1 fe80::aaaa:aaaa:aaaa:aaaa   DHCPv6  196 Advertise XID: 0xc32482 CID: 00040300020004000500 IAA: 2001:558:600a:7f:bbbb:bbbb:bbbb:bbbb

A類型 4 客戶端 ID是基於 UUID 的 DUID，長度應為 128 位元（16 位元組）。dhcpcd正在發送正確的長度，但康卡斯特的回應太短（8 個位元組）。

我嘗試透過發送顯式客戶端 IDdhcpcd -I 00:04:03:00:02:00:04:00:05:00 ...來匹配康卡斯特將其截斷的內容，但 tcpdump 表明此選項未生效。我還嘗試將其從類型 4（這是 RFC 指定的）更改為類型 9（不是），以防萬一dhcpcd不喜歡太短的類型 4 客戶端 ID，但dhcpcd仍然沒有使用它。

相關內容