Proxy
公共介面上的 Squid 代理超時 - 數據包在埠 3128 上失去
部分解決方案
事實證明，埠 3128 上的流量在通往我的 VPS 的途中失去了。我不確定這是 Linode 阻塞了這個埠，還是介於兩者之間。（我在其他雲上使用過同樣的代理，並且它有效。）
將埠更改為53128，它可以工作。
但是，我如何探測埠 3128 以檢查包被丟棄的位置？肯定是在他們到達我的 VPS 之前。
問題
我在執行 CentOS 6.7 的 VPS 中設置了 squid 代理，以便允許我在多個集群節點之間共享 Web 會話。
該代理在雲中執行，當所有節點都在同一個專用網路中時，
192.168.0.0/24一切正常。這週我在家裡部署了幾台伺服器來做一些很長的批處理作業，我需要通過我的代理進行連接。但是，squid 在我的公共界面上超時。
我
squid.conf幾乎允許每個傳入的連接，因為我受到限制iptables。但是，即使防火牆停止，我也無法通過 Internet 連接到我的代理。測試來自 VPS 集群的連接
注意：故意省略公共 IP 和主機名。
$ curl --proxy PUBLIC_HOSTNAME:3128 -v google.com.br * About to connect() to proxy PUBLIC_HOSTNAME port 3128 (#0) * Trying PUBLIC_IP... connected * Connected to PUBLIC_HOSTNAME (PUBLIC_IP) port 3128 (#0) [ OUTPUT OMITTED ] * Connection #0 to host PUBLIC_HOSTNAME left intact * Closing connection #0 $ curl --proxy PRIVATE_HOSTNAME:3128 -v google.com.br * About to connect() to proxy PRIVATE_HOSTNAME port 3128 (#0) * Trying PRIVATE_IP... connected * Connected to PRIVATE_HOSTNAME (PRIVATE_IP) port 3128 (#0) [ OUTPUT OMITTED ] * Connection #0 to host PRIVATE_HOSTNAME left intact * Closing connection #0在家測試連接（網際網路）
注意：故意省略公共 IP 和主機名。
埠 3128 上的數據包確實超時。埠 53128 上的數據包可以工作。
$ curl --proxy HOSTNAME:3128 -v google.com.br * About to connect() to proxy HOSTNAME port 3128 (#0) * Trying PUBLIC_IP... Connection timed out * couldn't connect to host * Closing connection #0 curl: (7) couldn't connect to host $ curl --proxy PUBLIC_HOSTNAME:53128 -v google.com.br * About to connect() to proxy PUBLIC_HOSTNAME port 53128 (#0) * Trying PUBLIC_IP... connected * Connected to PUBLIC_HOSTNAME (PUBLIC_IP) port 53128 (#0) [ OUTPUT OMITTED ] * Connection #0 to host PUBLIC_HOSTNAME left intact * Closing connection #0附帶說明一下，正如您從上面的輸出中看到的那樣，即使是在雲內部，也可以通過公共介面建立連接。
我的 VPS 託管在 Linode 上，他們的專用網路是通過虛擬介面建立的，所有流量都通過公共介面路由。無論如何，我認為這不是問題。
squid.conf
Squid 正在偵聽它的預設埠。
$ sudo netstat -ntlp | grep 3128 tcp 0 0 :::53128 :::* LISTEN 19282/(squid) tcp 0 0 :::3128 :::* LISTEN 19282/(squid)我的配置文件很標準，最後加了一個斗篷。
Squid 是通過 安裝的
yum，這是 CentOS 6.7 可用的軟體包。$ sudo cat /etc/squid/squid.conf # # Recommended minimum configuration: # acl manager proto cache_object acl localhost src 127.0.0.1/32 ::1 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1 # Example rule allowing access from your local networks. # Adapt to list your (internal) IP networks from where browsing # should be allowed #acl localnet src 10.0.0.0/8 # RFC1918 possible internal network #acl localnet src 172.16.0.0/12 # RFC1918 possible internal network #acl localnet src 192.168.0.0/16 # RFC1918 possible internal network #acl localnet src fc00::/7 # RFC 4193 local private network range #acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines visible_hostname cluster.proxy dns_nameservers 8.8.8.8 8.8.4.4 #hosts_file none hosts_file /etc/hosts # quick_abort_min 0 KB # quick_abort_max 0 KB strip_query_terms off log_icp_queries off client_db off buffered_logs on # half_closed_clients off connect_timeout 30 seconds forward_timeout 60 seconds request_timeout 60 seconds dns_timeout 30 seconds # positive_dns_ttl 8 hours # negative_dns_ttl 30 seconds acl localnet src all # Intentionally left open. Not sure if this is valid. acl ghome src OMITTED.ddns.net # Dynamic DNS for my home address acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl CONNECT method CONNECT # # Recommended minimum Access Permission configuration: # # Only allow cachemgr access from localhost http_access allow manager localhost http_access deny manager # Deny requests to certain unsafe ports #http_access deny !Safe_ports # Deny CONNECT to other than secure SSL ports #http_access deny CONNECT !SSL_ports # We strongly recommend the following be uncommented to protect innocent # web applications running on the proxy server who think the only # one who can access services on "localhost" is a local user #http_access deny to_localhost # # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS # # Example rule allowing access from your local networks. # Adapt localnet in the ACL section to list your (internal) IP networks # from where browsing should be allowed http_access allow localnet http_access allow localhost http_access allow ghome # Tried this rule for my home # And finally deny all other access to this proxy #http_access deny all http_access allow all # Tried this rule for world # Squid normally listens to port 3128 http_port 3128 http_port 53128 # We recommend you to use at least the following line. hierarchy_stoplist cgi-bin ? cache deny all # Uncomment and adjust the following to add a disk cache directory. #cache_dir ufs /var/spool/squid 100 16 256 # Leave coredumps in the first cache dir coredump_dir /var/spool/squid # Add any of your own refresh_pattern entries above these. refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 refresh_pattern . 0 20% 4320 # Hide Proxy from destination server # Needed to share sessions via off forwarded_for off request_header_access Allow allow all request_header_access Authorization allow all request_header_access WWW-Authenticate allow all request_header_access Proxy-Authorization allow all request_header_access Proxy-Authenticate allow all request_header_access Cache-Control allow all request_header_access Content-Encoding allow all request_header_access Content-Length allow all request_header_access Content-Type allow all request_header_access Date allow all request_header_access Expires allow all request_header_access Host allow all request_header_access If-Modified-Since allow all request_header_access Last-Modified allow all request_header_access Location allow all request_header_access Pragma allow all request_header_access Accept allow all request_header_access Accept-Charset allow all request_header_access Accept-Encoding allow all request_header_access Accept-Language allow all request_header_access Content-Language allow all request_header_access Mime-Version allow all request_header_access Retry-After allow all request_header_access Title allow all request_header_access Connection allow all request_header_access Proxy-Connection allow all request_header_access User-Agent allow all request_header_access Cookie allow all request_header_access All deny all有沒有辦法檢查我的連接是否到達 VPS？
我沒有找到超出它的魷魚日誌
access.log，這與我的家庭聯繫沒有任何關係；
原來這是 Linode 數據中心的問題。
traceroute指出數據包在到達 Linode 亞特蘭大數據中心時被丟棄。注意：故意省略伺服器公共 IP 和主機名
$ sudo traceroute -p 3128 HOSTNAME --tcp traceroute to HOSTNAME (PUBLIC_IP), 30 hops max, 60 byte packets 1 192.168.0.254 (192.168.0.254) 0.922 ms 1.337 ms 2.016 ms 2 200.150.94.3 (200.150.94.3) 11.970 ms 12.337 ms 12.699 ms 3 trunk11-src1km3a-src1cos.copel.net (200.150.92.107) 11.980 ms 12.928 ms 12.962 ms 4 177.84.164.33 (177.84.164.33) 14.230 ms 15.943 ms 16.306 ms 5 149.3.181.42 (149.3.181.42) 17.045 ms 17.889 ms 18.127 ms 6 xe-7-2-1.ashburn2.ash.seabone.net (195.22.199.187) 171.647 ms xe-0-1-2.ashburn2.ash.seabone.net (89.221.40.3) 163.118 ms 161.458 ms 7 xe-7-0-1.ashburn2.ash.seabone.net (195.22.199.189) 163.412 ms xe-2-2-2.ashburn2.ash.seabone.net (195.22.199.183) 159.763 ms xe-7-0-1.ashburn2.ash.seabone.net (195.22.199.189) 162.821 ms 8 ae13.er2.iad10.us.zip.zayo.com (64.125.12.1) 161.005 ms 160.879 ms 161.481 ms 9 ae7.er1.iad10.us.zip.zayo.com (64.125.25.49) 146.142 ms 144.668 ms 146.361 ms 10 ae6.cr1.dca2.us.zip.zayo.com (64.125.20.117) 147.399 ms 147.831 ms 148.792 ms 11 ae2.mpr4.atl6.us.zip.zayo.com (64.125.25.46) 150.200 ms ae4.mpr3.atl6.us.zip.zayo.com (64.125.31.197) 144.751 ms ae2.mpr4.atl6.us.zip.zayo.com (64.125.25.46) 146.808 ms 12 ae4.mpr3.atl6.us.zip.zayo.com (64.125.31.197) 143.534 ms 143.451 ms 146.218 ms 13 * * * ... 30 * * *如前所述，它在埠 53128 上通過。
$ sudo traceroute -p 53128 HOSTNAME --tcp traceroute to HOSTNAME (PUBLIC_IP), 30 hops max, 60 byte packets 1 192.168.0.254 (192.168.0.254) 0.931 ms 1.458 ms 1.968 ms 2 200.150.94.3 (200.150.94.3) 12.079 ms 12.222 ms 12.362 ms 3 trunk11-src1km3a-src1cos.copel.net (200.150.92.107) 51.764 ms 52.274 ms 52.466 ms 4 177.84.164.33 (177.84.164.33) 14.533 ms 14.910 ms 15.449 ms 5 149.3.181.42 (149.3.181.42) 16.408 ms 17.265 ms 17.720 ms 6 xe-2-2-2.ashburn2.ash.seabone.net (195.22.199.183) 171.688 ms xe-7-2-1.ashburn2.ash.seabone.net (195.22.199.187) 161.815 ms xe-0-1-2.ashburn2.ash.seabone.net (89.221.40.3) 162.661 ms 7 xe-2-3-1.ashburn2.ash.seabone.net (195.22.199.181) 163.044 ms xe-2-2-2.ashburn2.ash.seabone.net (195.22.199.183) 160.476 ms xe-7-0-2.ashburn2.ash.seabone.net (195.22.199.185) 161.247 ms 8 ae13.er2.iad10.us.zip.zayo.com (64.125.12.1) 162.917 ms 162.569 ms 164.899 ms 9 ae7.er1.iad10.us.zip.zayo.com (64.125.25.49) 149.290 ms 147.938 ms ae6.cr1.dca2.us.zip.zayo.com (64.125.20.117) 150.054 ms 10 ae2.mpr4.atl6.us.zip.zayo.com (64.125.25.46) 150.416 ms ae6.cr1.dca2.us.zip.zayo.com (64.125.20.117) 145.685 ms 146.062 ms 11 ae4.mpr3.atl6.us.zip.zayo.com (64.125.31.197) 145.271 ms ae2.mpr4.atl6.us.zip.zayo.com (64.125.25.46) 146.286 ms ae4.mpr3.atl6.us.zip.zayo.com (64.125.31.197) 143.456 ms 12 128.177.104.134.IPYX-092136-ZYO.zip.zayo.com (128.177.104.134) 143.646 ms ae4.mpr3.atl6.us.zip.zayo.com (64.125.31.197) 145.377 ms 143.066 ms 13 128.177.104.134.IPYX-092136-ZYO.zip.zayo.com (128.177.104.134) 147.494 ms 148.962 ms 148.619 ms 14 router1-atl.linode.com (64.22.106.10) 148.807 ms 146.101 ms PRIVATE_HOSTNAME.members.linode.com (PUBLIC_IP) 145.706 ms有了這個，我就可以打開一張支持票並得到我的肯定答案。我很高興這不是我的伺服器的問題。
你好呀，
我們進行了進一步調查，結果發現這實際上是我們亞特蘭大數據中心一直存在的問題，因此我們很抱歉未能盡快給您答复。目前我們正在努力讓這個埠暢通無阻，但我們無法給出時間估計。
同時，那個不同的埠對你有用嗎？如果您希望使用工作的 3128 埠，我也可以將您遷移到不同的數據中心——也許是加利福尼亞州弗里蒙特或新澤西州紐瓦克？
https://www.linode.com/speedtest讓我們知道。
問候， Roland Linode 支持團隊