Site Tools


dhcp_dns

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision Both sides next revision
dhcp_dns [2021/08/05 06:22]
hogwild
dhcp_dns [2021/08/05 06:24]
hogwild clarity, spelling
Line 1: Line 1:
- 
- 
 ====== DHCP/DNS ====== ====== DHCP/DNS ======
  
Line 11: Line 9:
 **Debug mode:** Checking this makes FreshTomato write detailed information the log file. **Debug mode:** Checking this makes FreshTomato write detailed information the log file.
  
-**Use received DNS with user-entered DNS: **Add DNS servers received from DHCP on your WAN connection to the static (manual) DNS server list. +**Use received DNS with user-entered DNS: **Add DNS servers received from DHCP on your WAN connection to the static (manual) DNS server list. See Basic/Network for more information. (Default: Disabled).
- +
-See Basic/Network for more information. (Default: Disabled).+
  
 **Prevent DNS-rebind attacks:** Enable DNS rebinding protection in dnsmasq. (Default: Enabled). **Prevent DNS-rebind attacks:** Enable DNS rebinding protection in dnsmasq. (Default: Enabled).
Line 31: Line 27:
   * Custom: This allows you to enter a custom Static DHCP lease time. \\ (Default: Same as Normal Lease Time).   * Custom: This allows you to enter a custom Static DHCP lease time. \\ (Default: Same as Normal Lease Time).
  
-**Announce IPv6 on LAN (SLAAC): **Enabling this turns on router advertisements for IPv6 //Stateless Address Autoconfiguration (SLAAC)//  protocol. This allows hosts to self-configure an IP address with minimal contact with a server. The client sends out an RS (router solicitation) ICMP packet. The nearest router responds with a RA (router advertisement) packet. The client uses the IPv6 prefix provided in the RA packet as the first 64 bits of its address. It then derives the last 64 bits of its address using the EUI-64 process or a randomizatiion algorithm.+**Announce IPv6 on LAN (SLAAC): **Enabling this turns on router advertisements for IPv6 //Stateless Address Autoconfiguration (SLAAC)//  protocol. This allows hosts to self-configure an IP address with minimal contact with a server. The client sends out an RS (router solicitation) ICMP packet. The nearest router responds with a RA (router advertisement) packet. The client uses the IPv6 prefix provided in the RA packet as the first 64 bits of its address. It then derives the last 64 bits of its address using the EUI-64 process or a randomization algorithm.
  
 **Announce IPv6 on LAN (DHCP):**  Enabling this makes FreshTomato turn on router advertisements using IPv6 DHCP. **Announce IPv6 on LAN (DHCP):**  Enabling this makes FreshTomato turn on router advertisements using IPv6 DHCP.
Line 51: Line 47:
 **Use Stubby (DNS-over-TLS):** This enhances DNS privacy. Checking this box enables Stubby, a DNS Stub resolver. DNS over TLS sends DNS queries over a secure connection, encrypted with TLS, the same technology that encrypts secure Web traffic. This prevents third parties from seeing your DNS queries. **Use Stubby (DNS-over-TLS):** This enhances DNS privacy. Checking this box enables Stubby, a DNS Stub resolver. DNS over TLS sends DNS queries over a secure connection, encrypted with TLS, the same technology that encrypts secure Web traffic. This prevents third parties from seeing your DNS queries.
  
-**WINS (for DHCP): **Here, you can specify the IP adddress of a WINS Server which will be given to DHCP clients. NOTE: This does NOT actually enable the WINS service. FreshTomato's WINS Server function is enabled on the USB and NAS/**[[:file_sharing|File Sharing]]** menu.+**WINS (for DHCP): **Here, you can specify the IP address of a WINS Server which will be given to DHCP clients. NOTE: This does NOT actually enable the WINS service. FreshTomato's WINS Server function is enabled on the USB and NAS/**[[:file_sharing|File Sharing]]** menu.
  
 Windows Internet Name Service (WINS) is a legacy computer name registration and resolution service that maps computer NetBIOS names to IP addresses. Officially, WINS is outdated and largely obsolete. DNS is supposed to have replaced most WINS functionality. However, Microsoft has not officially deprecated WINS. It may still be necessary for some Windows LAN browsing functions, especially on very old Windows versions. Windows Internet Name Service (WINS) is a legacy computer name registration and resolution service that maps computer NetBIOS names to IP addresses. Officially, WINS is outdated and largely obsolete. DNS is supposed to have replaced most WINS functionality. However, Microsoft has not officially deprecated WINS. It may still be necessary for some Windows LAN browsing functions, especially on very old Windows versions.
Line 67: Line 63:
 **Reduce Packet Size:** udhcpc (the DHCP client FreshTomato uses to obtain a WAN IP address) has a problem. It has a DHCP discovery packet size 590 bytes long. However, DHCP relay servers can only handle DHCP discovery packets up to 576 bytes. If there are DHCP relay servers between your FreshTomato router and your Internet provider's DHCP server, FreshTomato might fail to acquire a DHCP lease on the WAN interface. **Reduce Packet Size:** udhcpc (the DHCP client FreshTomato uses to obtain a WAN IP address) has a problem. It has a DHCP discovery packet size 590 bytes long. However, DHCP relay servers can only handle DHCP discovery packets up to 576 bytes. If there are DHCP relay servers between your FreshTomato router and your Internet provider's DHCP server, FreshTomato might fail to acquire a DHCP lease on the WAN interface.
  
-The extra bytes appeared to be entirely padding, and not necessary. FreshTomato developers eliminated the padding, which reduced udhcpc's DHCP discovery packet size to only 331 bytes. This 331 byte size eventually became FreshTomato's default setting. This way, udhcpc can succesfully obtain a DHCP lease from a provider which might have DHCP relays. It may be possible that some users may not be able to obtain a WAN IP address unless they disable this feature, however. (Default: Enabled).\\  \\  [[https://wiki.freshtomato.org/lib/exe/detail.php?id=dhcp_dns&media=d90d1b21f72f758269c6516f336b3b5f.png|{{:d90d1b21f72f758269c6516f336b3b5f.png}}]]+The extra bytes appeared to be entirely padding, and not necessary. FreshTomato developers eliminated the padding, which reduced udhcpc's DHCP discovery packet size to only 331 bytes. This 331 byte size eventually became FreshTomato's default setting. This way, udhcpc can successfully obtain a DHCP lease from a provider which might have DHCP relays. It may be possible that some users may not be able to obtain a WAN IP address unless they disable this feature, however. (Default: Enabled).\\  \\  [[https://wiki.freshtomato.org/lib/exe/detail.php?id=dhcp_dns&media=d90d1b21f72f758269c6516f336b3b5f.png|{{:d90d1b21f72f758269c6516f336b3b5f.png}}]]
  
  
dhcp_dns.txt · Last modified: 2021/09/07 17:42 by techie007