Ssh
SSH 無法通過 IPSec 隧道工作 (Strongswan)
我在雲虛擬機上配置了一個小型網路。此虛擬機有一個靜態 IP 地址分配給我將呼叫的 eth0 介面 $ EXTIP. mydomain.com points to $ 擴展。在裡面,我有一些 linux 容器,它們通過子網 10.0.0.0/24 中的 DHCP 獲取它們的 ip(我稱為虛擬介面nat)。他們執行一些可以通過 DNAT 訪問的服務。然後我想通過IPSec隧道連接到這些容器,所以我配置了StrongSwan。
ipsec.conf:
conn %default dpdaction=none rekey=no conn remote keyexchange=ikev2 ike=######## left=[$EXTIP] leftsubnet=10.0.1.0/24,10.0.0.0/24 leftauth=pubkey lefthostaccess=yes leftcert=########.pem leftfirewall=yes leftid="#########" right=%any rightsourceip=10.0.1.0/24 rightauth=######## rightid=%any rightsendcert=never eap_identity=%any auto=add type=tunnel
一切正常,IPSec 客戶端獲得 10.0.1.0/24 子網的 IP,並且可以訪問容器子網。我的問題是我無法通過隧道獲得 SSH 連接。它根本不起作用,ssh 客戶端不產生任何輸出。用 tcpdump 嗅探會給出:
tcpdump:
09:50:29.648206 ARP, Request who-has 10.0.0.1 tell mydomain.com, length 28 09:50:29.648246 ARP, Reply 10.0.0.1 is-at 00:ff:aa:00:00:01 (oui Unknown), length 28 09:50:29.648253 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [S], seq 4007849772, win 29200, options [mss 1460,sackOK,TS val 1151153 ecr 0,nop,wscale 7], length 0 09:50:29.648296 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [S.], seq 2809522632, ack 4007849773, win 14480, options [mss 1460,sackOK,TS val 11482992 ecr 1151153,nop,wscale 6], length 0 09:50:29.677225 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 2809522633, win 229, options [nop,nop,TS val 1151162 ecr 11482992], length 0 09:50:29.679370 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [P.], seq 0:23, ack 1, win 229, options [nop,nop,TS val 1151162 ecr 11482992], length 23 09:50:29.679403 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], ack 24, win 227, options [nop,nop,TS val 11483002 ecr 1151162], length 0 09:50:29.684337 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1:32, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 31 09:50:29.685471 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 32:1480, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 1448 09:50:29.685519 IP mydomain.com > 10.0.0.1: ICMP mydomain.com unreachable - need to frag (mtu 1422), length 556 09:50:29.685567 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 32:1402, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 1370 09:50:29.685572 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 1402:1480, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 78 09:50:29.714601 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 32, win 229, options [nop,nop,TS val 1151173 ecr 11483003], length 0 09:50:29.714642 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1480:1600, ack 24, win 227, options [nop,nop,TS val 11483012 ecr 1151173], length 120 09:50:29.723649 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [P.], seq 1393:1959, ack 32, win 229, options [nop,nop,TS val 1151174 ecr 11483003], length 566 09:50:29.723677 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], ack 24, win 227, options [nop,nop,TS val 11483015 ecr 1151173,nop,nop,sack 1 {1394:1960}], length 0 09:50:29.725688 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 1480, win 251, options [nop,nop,TS val 1151177 ecr 11483003], length 0 09:50:29.952394 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1480:1600, ack 24, win 227, options [nop,nop,TS val 11483084 ecr 1151173,nop,nop,sack 1 {1394:1960}], length 120 09:50:29.981056 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 1600, win 251, options [nop,nop,TS val 1151253 ecr 11483084,nop,nop,sack 1 {1480:1600}], length 0
如果你需要,這是我的 iptables 配置文件:
iptables:
*filter :INPUT ACCEPT [144:9669] :FORWARD DROP [0:0] :OUTPUT ACCEPT [97:15649] :interfacce-trusted - [0:0] :porte-trusted - [0:0] -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A FORWARD -j interfacce-trusted -A FORWARD -j porte-trusted -A FORWARD -j REJECT --reject-with icmp-host-unreachable -A FORWARD -d 10.0.0.1/32 -p tcp -m tcp --dport 80 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A FORWARD -d 10.0.0.1/32 -p tcp -m tcp --dport 443 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A FORWARD -d 10.0.0.3/32 -p tcp -m tcp --dport 1234 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A interfacce-trusted -i nat -j ACCEPT -A porte-trusted -d 10.0.0.1/32 -p tcp -m tcp --dport 80 -j ACCEPT -A porte-trusted -d 10.0.0.1/32 -p tcp -m tcp --dport 443 -j ACCEPT -A porte-trusted -d 10.0.0.3/32 -p tcp -m tcp --dport 1234 -j ACCEPT COMMIT *nat :PREROUTING ACCEPT [10:600] :INPUT ACCEPT [10:600] :OUTPUT ACCEPT [4:268] :POSTROUTING ACCEPT [18:1108] -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.1:80 -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 443 -j DNAT --to-destination 10.0.0.1:443 -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 8069 -j DNAT --to-destination 10.0.0.3:1234 -A POSTROUTING -s 10.0.0.0/24 -o eth0 -m policy --dir out --pol ipsec -j ACCEPT -A POSTROUTING -s 10.0.1.0/24 -o nat -j MASQUERADE -A POSTROUTING -s 10.0.0.0/24 -o eth0 -j MASQUERADE COMMIT
可能我錯過了一些愚蠢的東西……在此先感謝您的幫助:))
問題是數據包碎片。通過 mangle 表中的一個簡單規則來管理 MSS,我解決了我的問題 :)
iptables -t mangle -A FORWARD -o eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1361:1536 -j TCPMSS --set-mss 1360