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advanced-firewall [2022/01/18 19:14] – rs232 | advanced-firewall [2023/05/28 05:39] (current) – [Multicast] -condense, list/explain additional features of new IGMPv2 messages hogwild | ||
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+ | ====== Firewall ====== | ||
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+ | The Firewall page allows you to configure options to protect or facilitate various types of network communications. | ||
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===== Firewall ===== | ===== Firewall ===== | ||
- | The Firewall page allows | + | {{: |
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+ | \\ **WAN interfaces respond to ping and traceroute: | ||
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+ | **Limit communication to: **This specifies the maximum number of requests per second to which the Firewall will reply. Setting a limit number is recommended to prevent DDoS attacks.\\ | ||
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+ | \\ | ||
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+ | **Enable TCP SYN cookies: | ||
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+ | **Enable DCSP Fix: **Checking this enables a workaround for packet marking, a well-known issue related to DSCP when connected to Comcast. | ||
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+ | **Allow DHCP Spoofing: ** | ||
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+ | **Smart MTU black hole detection: | ||
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+ | |||
+ | ===== NAT ===== | ||
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+ | **NAT loopback:** This technique allows LAN devices to access each other via the router' | ||
+ | |||
+ | * All | ||
+ | * Forwarded Only | ||
+ | * Disabled | ||
+ | |||
+ | \\ | ||
+ | |||
+ | {{:: | ||
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+ | **NAT target** - This defines the way NAT is implemented for use during loopback. Masquerade is the default, but involves an additional lookup. ad the mapping of done towards an interface. SNAT is minutely faster, as the NAT mapping points directly to the destination IP and so it bypasses the lookup stage. However, SNAT is less reliable than Masquerade. | ||
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+ | \\ | ||
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+ | ===== Multicast ===== | ||
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+ | \\ \\ {{: | ||
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+ | **Enable IGMP proxy** - Checking this enables the IGMP (Internet Group Management Protocol) service. | ||
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+ | LAN0 - LAN3 Specifies which bridges will participate in IGMP, with the router acting as a proxy between selected LANs. This allows IGMP to work between VLANs. | ||
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+ | * LAN0 - Checking this means the LAN0 bridge will participate in IGMP proxy. | ||
+ | * LAN1 - Checking this means the LAN1 bridge will participate in IGMP proxy. | ||
+ | * LAN2 - Checking this means the LAN2 bridge will participate in IGMP proxy. | ||
+ | * LAN3 - Checking this means the LAN3 bridge will participate in IGMP proxy. | ||
+ | |||
+ | \\ | ||
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+ | **Enable quick leave** - This is a feature of IGMP v2 and later. Enabling this allows the router to stop streaming multicast to an IP address as soon as that device sends a "quick leave" IGMP packet. | ||
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+ | **Custom Configuration** - This option allows you to set advanced parameters for the IGMP proxy daemon. Consult official IGMP documentation before using this.\\ | ||
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+ | \\ {{: | ||
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+ | **Enable Udpxy** - Like IGMP proxy, Udpxy allows multicast | ||
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+ | **Upstream interface** - Here, enter the stream source is expected to live. (Default: blank). | ||
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+ | **LAN0/ | ||
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+ | **Enable client statistics** - Enabling this causes FreshTomato to collect statistics about Udpxy clients. | ||
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+ | **Max clients - ** This represents the maximum number of simultaneous Udpxy clients. Udpxy is is a lightweight protocol, and only works well for a limited number of clients. For this reason, you might want to impose a maximum limit. | ||
+ | |||
+ | **Udpxy port**- This specifies the port on which you can recive Udpxy information from your router.\\ | ||
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+ | **Efficient Multicast Forwarding (IGMP Snooping) -** IGMP snooping makes the router' | ||
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+ | However, caution is advised. IGMP Snooping can interfere with proper functioning of UPnP or DLNA. This can make Multicast configuration errors or deficiencies appear as UPnP issues. Enabling IGMP snooping on a router' | ||
- | {{: | + | A common symptom of this is a network host (say, a Smart TV) which appears after it's powered on, but then " |
- | **WAN interfaces respond to ping and traceroute** - When enabled | + | |
- | **Limit communication to**: This number imposes | + | |
- | {{: | + | **Force IGMPv2** - IGMPv2 enhances IGMP with additional messages/ |
- | **Enable TCP SYN cookies** - Enabling this will protect the router from SYN Flood attacks via a well known technique called SYN cookies. This technique encodes info from the SYN packet into the responce (SYN/ACK). Please note, despite being a standard technique enabling this option imposes some secondary limitation some old TCP/IP staks might not be easy to handle\\ | + | |
- | **Enable DCSP Fix** - This enables | + | |
- | **IPv6 IPSec Passthrough** - FIXME\\ | + | |
- | {{:pasted: | + | Other features of IGMPv2 include: |
- | **NAT loopback** - NAT loopback a.k.a Hairpinning is a well know technique that allows LAN devices to access another LAN device via the WAN interface of your router. This is common practice when calling e.g. the DDNS domain of your router from the LAN for administration purpose. Please | + | |
- | **NAT target** - Define the way NAT is implemented for the sake of Hairpinning. Masquerade is the default however this involves an additional lookup ad the mapping of done towards an interface. SNAT is faster (if ever measurable) as the NAT mapping point directly to the destination IP hence bypassing the lookup stage. | + | |
- | Multicast\\ | + | Group specific membership query. The router can now send a membership query for a specific group address. When the router |
- | {{: | + | |
- | **Enable IGMP proxy** - Runs the IGMP (Internet Group Management Protocol) | + | |
- | **LAN0/ | + | |
- | **Enable quick leave** - This is a feature of IGMP v2 and allows the router | + | |
- | **Custom Configuration** - This option allows you to set up some advanced parameters for the IGMP proxy daemon. Make sure to consult the official documentation.\\ | + | |
- | {{: | + | MRT (Maximum Response Time) field. This new field in query messages specifies how much time hosts have to respond |
- | **Enable Udpxy** - Similarly to IGMP proxy Udpxy allows multicast communication between sender and receiver sitting | + | |
- | **Upstream interface** - leave empty for default - Defines where the stream source is expected | + | |
- | **LAN0/ | + | |
- | **Enable client statistics** - As the option suggest if enabled statistical information about the clients is collected.\\ | + | |
- | **Max clients** - Considering this is a lightwave protocol it works well for a limited number of clients, you might want to impose a maximum number if any.\\ | + | |
- | **Udpxy port**- This is where you can consult | + | |
- | {{: | + | Querier election process. When two routers are connected |
- | **Efficient Multicast Forwarding (IGMP Snooping)** - IGMP snooping is a way to have the switch (router) facilitating | + | |
- | **Force IGMPv2** - IGMPv2 enhances the IGMP communication supporting additional messages/ | + | |