(外部ファイアウォール)IPv4アドレスを持つWebサーバー(Ubuntu 18 LTSを搭載したVMware-VM)で、次の操作を行いました。
apt-get install --no-install-recommends ufw
ufw deny from <some chinese hacker IP> to any # only this is reported by ufw status
1日に数十回システムログを入力します(<
山かっこ内の値は説明に置き換えられます>
)。
kernel: [UFW BLOCK] IN=ens192 OUT= MAC=<local MAC>:<gateway MAC>:08:00 SRC=<various source IPs> DST=<local IP> LEN=40 TOS=0x00 PREC=0x00 TTL=<values between 44 and 243> ID=0 DF PROTO=TCP SPT=<varying ephemeral ports> DPT=443 WINDOW=0 RES=0x00 RST URGP=0
ほとんどのブロックされたパケットはこのパターンと同じです。
時にはLEN
40ではなく42またはID
64、16273から61118の間の値で、時にはDon'tfragmentビットが設定されず、> 0がDF
代わりにACK
設定されることがあります。 Webサーバーがダウンしているという苦情は受け付けられていないため、ブロックにもかかわらずすべてがうまく機能しているとします。ブロックしようとした中国のハッカーIPが表示されませんでした。 (コマンドラインに記録されたIPを指定していません。)WIN
RST
SRC
ufw
これは、接続が閉じることを防ぐ(「リセット」)という意味ですか?
ufw
このパケットはなぜブロックされますか?彼らに何の問題がありますか?
何ですかID
?man ufw
ロギングman iptables
形式もありません。ウィキペディアは役に立ちません。
# ufw status
Status: active
To Action From
-- ------ ----
Anywhere DENY <chinese hacker IP as mentioned above>
# iptables -L -v -n
Chain INPUT (policy ACCEPT 520 packets, 18720 bytes)
pkts bytes target prot opt in out source destination
2051M 11T ufw-before-logging-input all -- * * 0.0.0.0/0 0.0.0.0/0
2051M 11T ufw-before-input all -- * * 0.0.0.0/0 0.0.0.0/0
13M 739M ufw-after-input all -- * * 0.0.0.0/0 0.0.0.0/0
13M 739M ufw-after-logging-input all -- * * 0.0.0.0/0 0.0.0.0/0
13M 739M ufw-reject-input all -- * * 0.0.0.0/0 0.0.0.0/0
13M 739M ufw-track-input all -- * * 0.0.0.0/0 0.0.0.0/0
Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ufw-before-logging-forward all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ufw-before-forward all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ufw-after-forward all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ufw-after-logging-forward all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ufw-reject-forward all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ufw-track-forward all -- * * 0.0.0.0/0 0.0.0.0/0
Chain OUTPUT (policy ACCEPT 20633 packets, 1958K bytes)
pkts bytes target prot opt in out source destination
1743M 11T ufw-before-logging-output all -- * * 0.0.0.0/0 0.0.0.0/0
1743M 11T ufw-before-output all -- * * 0.0.0.0/0 0.0.0.0/0
12M 915M ufw-after-output all -- * * 0.0.0.0/0 0.0.0.0/0
12M 915M ufw-after-logging-output all -- * * 0.0.0.0/0 0.0.0.0/0
12M 915M ufw-reject-output all -- * * 0.0.0.0/0 0.0.0.0/0
12M 915M ufw-track-output all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-after-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-input (1 references)
pkts bytes target prot opt in out source destination
0 0 ufw-skip-to-policy-input udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:137
0 0 ufw-skip-to-policy-input udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:138
0 0 ufw-skip-to-policy-input tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:139
0 0 ufw-skip-to-policy-input tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:445
0 0 ufw-skip-to-policy-input udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:67
0 0 ufw-skip-to-policy-input udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:68
0 0 ufw-skip-to-policy-input all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type BROADCAST
Chain ufw-after-logging-forward (1 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 10 LOG flags 0 level 4 prefix "[UFW BLOCK] "
Chain ufw-after-logging-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-logging-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-forward (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 3
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 11
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 12
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 8
0 0 ufw-user-forward all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-before-input (1 references)
pkts bytes target prot opt in out source destination
921M 3537G ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
1115M 7461G ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
106K 4375K ufw-logging-deny all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate INVALID
106K 4375K DROP all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate INVALID
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 3
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 11
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 12
1149K 50M ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmptype 8
1062K 348M ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp spt:67 dpt:68
13M 739M ufw-not-local all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT udp -- * * 0.0.0.0/0 224.0.0.251 udp dpt:5353
45 5760 ACCEPT udp -- * * 0.0.0.0/0 239.255.255.250 udp dpt:1900
13M 739M ufw-user-input all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-before-logging-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-output (1 references)
pkts bytes target prot opt in out source destination
921M 3537G ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0
810M 7485G ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
12M 915M ufw-user-output all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-logging-allow (0 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 10 LOG flags 0 level 4 prefix "[UFW ALLOW] "
Chain ufw-logging-deny (2 references)
pkts bytes target prot opt in out source destination
94170 3813K RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate INVALID limit: avg 3/min burst 10
4828 202K LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 10 LOG flags 0 level 4 prefix "[UFW BLOCK] "
Chain ufw-not-local (1 references)
pkts bytes target prot opt in out source destination
13M 737M RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type LOCAL
49698 1793K RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type MULTICAST
0 0 RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type BROADCAST
0 0 ufw-logging-deny all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 10
0 0 DROP all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-reject-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-forward (0 references)
pkts bytes target prot opt in out source destination
0 0 DROP all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-skip-to-policy-input (7 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-skip-to-policy-output (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-track-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-input (1 references)
pkts bytes target prot opt in out source destination
13M 737M ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
Chain ufw-track-output (1 references)
pkts bytes target prot opt in out source destination
13M 737M RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type LOCAL
49698 1793K RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type MULTICAST
0 0 RETURN all -- * * 0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst-type BROADCAST
0 0 ufw-logging-deny all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 10
0 0 DROP all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-reject-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-forward (0 references)
pkts bytes target prot opt in out source destination
0 0 DROP all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-skip-to-policy-input (7 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-skip-to-policy-output (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-track-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-input (1 references)
pkts bytes target prot opt in out source destination
13M 737M ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
Chain ufw-track-output (1 references)
pkts bytes target prot opt in out source destination
6953K 437M ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
387K 31M ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 ctstate NEW
Chain ufw-user-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-input (1 references)
pkts bytes target prot opt in out source destination
0 0 DROP all -- * * <chinese hacker IP> 0.0.0.0/0
Chain ufw-user-limit (0 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 3/min burst 5 LOG flags 0 level 4 prefix "[UFW LIMIT BLOCK] "
0 0 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
Chain ufw-user-limit-accept (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0
Chain ufw-user-logging-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-output (1 references)
pkts bytes target prot opt in out source destination