Manual:IP/Proxy
Applies to RouterOS: v3, v4
Summary
Sub-menu: /ip proxy
Standards: RFC 1945, RFC 2616
MikroTik RouterOS performs proxying of HTTP and HTTP-proxy (for FTP, HTTP and HTTPS protocols) requests. Proxy server performs Internet object cache function by storing requested Internet objects, i.e., data available via HTTP and FTP protocols on a system positioned closer to the recipient in the form of speeding up customer browsing by delivering them requested file copies from proxy cache at local network speed. MikroTik RouterOS implements the following proxy server features:
- Regular HTTP proxy – customer (itself) specify what is proxy server for him
- Transparent proxy – customer does not know about the proxy being enabled and there isn’t need any additional configuration for web browser of client.
- Access list by source, destination, URL and requested method (HTTP firewall)
- Cache access list to specify which objects to cache, and which not.
- Direct Access List – to specify which resources should be accessed directly, and which - through another proxy server
- Logging facility – allows to get and to store information about proxy operation
- Parent proxy support – allows to specify other proxy server, ('if they don’t have the requested object ask their parents, or to the original server.)
A proxy server usually is placed at various points between users and the destination server (also known as origin server) on the Internet. (see Figure 10.1).
A Web proxy (cache) watches requests coming from client, saving copies of the responses for itself. Then, if there is another request for the same URL, it can use the response that it has, instead of asking the origin server for it again. If proxy has not requested file, it downloads that from the original server.
There can be many potential purpose of proxy server:
- To decrease access speed to resources (it takes less time for the client to get the object).
- Works as HTTP firewall (deny access to undesirable web pages),
Allows to filter web content (by specific parameters, like source address, destination address and port, URL, HTTP request method) scan outbound content, e.g., for data leak protection.
Note: it may be useful to have Web proxy running even with no cache when you want to use it only as something like HTTP and FTP firewall (for example, denying access undesired web pages or deny specific type of files e.g. .mp3 files) or to redirect requests to external proxy (possibly, to a proxy with caching functions) transparently.
General
Sub-menu: /ip proxy
| Property | Description |
|---|---|
| always-from-cache (yes | no; Default: no) | |
| cache-administrator (string; Default: webmaster) | Administrator's e-mail displayed on proxy error page |
| cache-hit-dscp (integer: 0..63; Default: 4) | |
| cache-on-disk (yes | no; Default: no) | |
| max-cache-size (none | unlimited | integer: 0..4294967295; Default: none) | Specifies the maximal cache size, measured in kibibytes |
| max-client-connections (integer: 1..5000; Default: 600) | Maximal number of connections accepted from clients (any further connections will be rejected) |
| max-fresh-time (time; Default: 3d) | Maximal time to store a cached object. The validity period of an object is is usually defined by the object itself, but in case it is set too high, you can override the maximal value |
| max-server-connections (integer: 1..5000; Default: 600) | Maximal number of connections made to servers (any further connections from clients will be put on hold until some server connections will terminate) |
| parent-proxy (Ip4 | ip6; Default: 0.0.0.0) | IP address and port of another HTTP proxy to redirect all requests to. If set to 0.0.0.0 parent proxy is not used. |
| parent-proxy-port (integer: 0..65535; Default: 0) | Port that parent proxy is listening on. |
| port (integer: 0..65535; Default: 8080) | TCP port the proxy server will be listening on. This port have to be specified on all clients that want to use the server as HTTP proxy. Transparent (with zero configuration for clients) proxy setup can be made by redirecting HTTP requests to this port in IP firewall using destination NAT feature |
| serialize-connections (yes | no; Default: no) | |
| src-address (Ip4 | Ip6; Default: 0.0.0.0) | Proxy will use specified address when connecting to parent proxy or web site. If set to 0.0.0.0 then appropriate IP address will be taken from routing table. |
Menu Specific commands
Example
To enable the proxy on port 8000:
[admin@MikroTik] ip proxy> set enabled=yes port=8000
[admin@MikroTik] ip proxy> print
enabled: yes
src-address: 0.0.0.0
port: 8000
parent-proxy: 0.0.0.0:0
cache-drive: system
cache-administrator: "dmitry@mikrotik.com"
max-disk-cache-size: none
max-ram-cache-size: 100000KiB
cache-only-on-disk: yes
maximal-client-connections: 1000
maximal-server-connections: 1000
max-object-size: 2000KiB
max-fresh-time: 3d
[admin@MikroTik] ip proxy>
Remember to secure your proxy by preventing unauthorized access to it, otherwise it may be used as an open proxy. Also you need to setup destination NAT in order to utilize transparent proxying facility:
[admin@MikroTik] ip firewall nat> add chain=dstnat protocol=tcp dst-port=80 action=redirect to-ports=8000 [admin@MikroTik] ip firewall nat> print Flags: X - disabled, I - invalid, D - dynamic 0 chain=dstnat protocol=tcp dst-port=80 action=redirect to-ports=8000 [admin@MikroTik] ip firewall nat>
Access List
Sub-menu: /ip proxy access
Access list is configured like a regular firewall rules. Rules are processed from the top to the bottom. First matching rule specifies decision of what to do with this connection. There is a total of 6 classifiers that specify matching constraints. If none of these classifiers is specified, the particular rule will match every connection. If connection is matched by a rule, action property of this rule specifies whether connection will be allowed or not. If the particular connection does not match any rule, it will be allowed.
| Property | Description |
|---|---|
| action (allow | deny; Default: allow) | Specifies whether to pass or deny matched packets |
| dst-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Destination address of the target server. |
| dst-host (string; Default: ) | IP address or DNS name used to make connection the target server (this is the string user wrote in browser before specifying port and path to a particular web page |
| dst-port (integer[-integer[,integer[,...]]]: 0..65535; Default: ) | List or range of ports the packet is destined to |
| local-port (integer: 0..65535; Default: ) | Specifies the port of the web proxy via which the packet was received. This value should match one of the ports web proxy is listening on. |
| method (any | connect | delete | get | head | options | post | put | trace; Default: ) | HTTP method used in the request (see HTTP Methods section in the end of this document) |
| path (string; Default: ) | Name of the requested page within the target server (i.e. the name of a particular web page or document without the name of the server it resides on) |
| redirect-to (string; Default: ) | In case access is denied by this rule, the user shall be redirected to the URL specified here |
| src-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Source address of the connection originator. |
Read only properties:
| Property | Description |
|---|---|
| hits (integer) | Count of requests that were matched by this rule |
Wildcard properties (dst-host and dst-path) match a complete string (i.e., they will not match "example.com" if they are set to "example"). Available wildcards are '*' (match any number of any characters) and '?' (match any one character). Regular expressions are also accepted here, but if the property should be treated as a regular expression, it should start with a colon (':'). Small hits in using regular expressions: \\ symbol sequence is used to enter \ character in console \. pattern means . only (in regular expressions single dot in pattern means any symbol) to show that no symbols are allowed before the given pattern, we use ^ symbol at the beginning of the pattern to specify that no symbols are allowed after the given pattern, we use $ symbol at the end of the pattern to enter [ or ] symbols, you should escape them with backslash \. It is strongly recommended to deny all IP addresses except those behind the router as the proxy still may be used to access your internal-use-only (intranet) web servers. Also, consult examples in Firewall Manual on how to protect your router.
Direct Access
Sub-menu: /ip proxy direct
If parent-proxy property is specified, it is possible to tell proxy server whether to try to pass the request to the parent proxy or to resolve it connecting to the requested server directly. Direct Access List is managed just like Proxy Access List described in the previous chapter except the action argument.
Unlike the access list, the direct proxy access list has default action equal to deny. It takes place when no rules are specified or a particular request did not match any rule.
| Property | Description |
|---|---|
| action (allow | deny; Default: allow) | Specifies the action to perform on matched packets:
|
| dst-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Destination address of the target server. |
| dst-host (string; Default: ) | IP address or DNS name used to make connection the target server (this is the string user wrote in browser before specifying port and path to a particular web page |
| dst-port (integer[-integer[,integer[,...]]]: 0..65535; Default: ) | List or range of ports used by connection to target server. |
| local-port (integer: 0..65535; Default: ) | Specifies the port of the web proxy via which the packet was received. This value should match one of the ports web proxy is listening on. |
| method (any | connect | delete | get | head | options | post | put | trace; Default: ) | HTTP method used in the request (see HTTP Methods section in the end of this document) |
| path (string; Default: ) | Name of the requested page within the target server (i.e. the name of a particular web page or document without the name of the server it resides on) |
| src-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Source address of the connection originator. |
Read only properties:
| Property | Description |
|---|---|
| hits (integer) | Count of requests that were matched by this rule |
Cache Management
Sub-menu: /ip proxy cache
Cache access list specifies, which requests (domains, servers, pages) have to be cached locally by web proxy, and which not. This list is implemented exactly the same way as web proxy access list. Default action is to cache object (if no matching rule is found).
| Property | Description |
|---|---|
| action (allow | deny; Default: allow) | Specifies the action to perform on matched packets:
|
| dst-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Destination address of the target server |
| dst-host (string; Default: ) | IP address or DNS name used to make connection the target server (this is the string user wrote in browser before specifying port and path to a particular web page |
| dst-port (integer[-integer[,integer[,...]]]: 0..65535; Default: ) | List or range of ports the packet is destined to. |
| local-port (integer: 0..65535; Default: ) | Specifies the port of the web proxy via which the packet was received. This value should match one of the ports web proxy is listening on. |
| method (any | connect | delete | get | head | options | post | put | trace; Default: ) | HTTP method used in the request (see HTTP Methods section in the end of this document) |
| path (string; Default: ) | Name of the requested page within the target server (i.e. the name of a particular web page or document without the name of the server it resides on) |
| src-address (Ip4[-Ip4 | /0..32] | Ip6/0..128; Default: ) | Source address of the connection originator |
Read only properties:
| Property | Description |
|---|---|
| hits (integer) | Count of requests that were matched by this rule |
Menu Specific commands
Connections
Sub-menu: /ip proxy connections
This menu conntains the list of current connections the proxy is serving.
Read only properties:
| Property | Description |
|---|---|
| client () | |
| dst-address (Ip4 | Ip6) | IPv4/Ipv6 destination address of the connection |
| protocol (string) | Protocol name |
| rx-bytes (integer) | The amount of bytes received by the client |
| server () | |
| src-address (Ip4 | Ip6) | Ipv4/ipv6 address of the connection originator |
| state (closing | connecting | converting | hotspot | idle | resolving | rx-header | tx-body | tx-eof | tx-header | waiting) | Connection state:
|
| tx-bytes (integer) | The amount of bytes sent by the client |
Cache Inserts
Sub-menu: /ip proxy inserts
This menu shows statistics on objects stored in cache (cache inserts).
Read only properties:
| Property | Description |
|---|---|
| denied (integer) | Number of inserts denied by the caching list. |
| errors (integer) | Number of disk or other system-related errors |
| no-memory (integer) | Number of objects not stored because there was not enough memory |
| successes (integer) | Number of successfull cache inserts. |
| too-large (integer) | Number of objects too large to store |
Cache Lookups
Sub-menu: /ip proxy lookup
This menu shows statistics on objects read from cache (cache lookups).
Read only properties:
| Property | Description |
|---|---|
| denied (integer) | Number of requests denied by the access list. |
| expired (integer) | Number of requests found in cache, but expired, and, thus, requested from an external server |
| no-expiration-info (integer) | Conditional request received for a page that does not have the information to compare the request with |
| non-cacheable (integer) | Number of requests requested from the external servers unconditionally (as their caching is denied by the cache access list) |
| not-found (integer) | Number of requests not found in the cache, and, thus, requested from an external server (or parent proxy if configured accordingly) |
| successes (integer) | Number of requests found in the cache. |
Cache Contents
Sub-menu: /ip proxy cache-contents
This menu shows cached contents.
Read only properties:
| Property | Description |
|---|---|
| file-size (integer) | Cached object size |
| last-accessed (time) | |
| last-accessed-time (time) | |
| last-modified (time) | |
| last-modified-time (time) | |
| uri (string) |
HTTP Methods
Options
This method is a request of information about the communication options available on the chain between the client and the server identified by the Request-URI. The method allows the client to determine the options and (or) the requirements associated with a resource without initiating any resource retrieval
GET
This method retrieves whatever information identified by the Request-URI. If the Request-URI refers to a data processing process than the response to the GET method should contain data produced by the process, not the source code of the process procedure(-s), unless the source is the result of the process.
The GET method can become a conditional GET if the request message includes an If-Modified-Since, If-Unmodified-Since, If-Match, If-None-Match, or If-Range header field. The conditional GET method is used to reduce the network traffic specifying that the transfer of the entity should occur only under circumstances described by conditional header field(-s).
The GET method can become a partial GET if the request message includes a Range header field. The partial GET method intends to reduce unnecessary network usage by requesting only parts of entities without transferring data already held by client.
The response to a GET request is cacheable if and only if it meets the requirements for HTTP caching.
HEAD
This method shares all features of GET method except that the server must not return a message-body in the response. This retrieves the metainformation of the entity implied by the request which leads to a wide usage of it for testing hypertext links for validity, accessibility, and recent modification.
The response to a HEAD request may be cacheable in the way that the information contained in the response may be used to update previously cached entity identified by that Request-URI.
POST
This method requests that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI.
The actual action performed by the POST method is determined by the origin server and usually is Request-URI dependent.
Responses to POST method are not cacheable, unless the response includes appropriate Cache-Control or Expires header fields.
PUT
This method requests that the enclosed entity be stored under the supplied Request-URI. If another entity exists under specified Request-URI, the enclosed entity should be considered as updated (newer) version of that residing on the origin server. If the Request-URI is not pointing to an existing resource, the origin server should create a resource with that URI.
If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries should be treated as stale. Responses to this method are not cacheable.
TRACE
This method invokes a remote, application-layer loop-back of the request message. The final recipient of the request should reflect the message received back to the client as the entity-body of a 200 (OK) response. The final recipient is either the origin server or the first proxy or gateway to receive a Max-Forwards value of 0 in the request. A TRACE request must not include an entity.
Responses to this method MUST NOT be cached.
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