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toh:tp-link:archer_c2_ac750 [2021/07/16 15:52] – Fixed the model name in serial parameters table grzesiek11toh:tp-link:archer_c2_ac750 [2022/06/29 14:20] – [Switch] Add more details about using VLAN IDs above 31 in the outer switch configuration znark
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 If you encounter timeouts, you might want to put a switch between your router and client to facilitate the flashing process. The tips below might not be needed after that. If you encounter timeouts, you might want to put a switch between your router and client to facilitate the flashing process. The tips below might not be needed after that.
- 
-A few users reported that flashing via TFTP server was only possible when the option "Use anticipation window of" with 1000 bytes was enabled in TFTPD32 for Windows. So, if your flashing process hang at some point, restart the process with this option enabled. 
  
 Also, you //might// have to lower your ethernet link to 10 Mbps Half Duplex in order to finish the process. Also, you //might// have to lower your ethernet link to 10 Mbps Half Duplex in order to finish the process.
 +
 +</WRAP>
 +
 +
 +<WRAP center round important 95%>
 +
 +A few users reported that flashing via TFTP is not always possible on some devices. Apparently there was a slight hardware change in some produced devices that causes TFTP inside u-boot to expect [[https://datatracker.ietf.org/doc/html/rfc7440|RFC7440]] behavior without actually requesting RFC7440 behavior.
 +There is a [[https://forum.openwrt.org/t/tftp-download-from-tp-link-archer-c2-does-not-work-properly/65531/|forum thread]] with a detailed analysis of the issue and possible solutions.
 +
 +**TLDR:**
 +
 +If you want to stick to flashing via TFTP:
 +  * on Windows use [[https://pjo2.github.io/tftpd64/|TFTPD32/64]] with the option ''Use anticipation window of 1000 bytes''
 +  * on every other platform you could use [[https://github.com/apardyl/PyTFTPd|apardyl/PyTFTPd]] with the patch provided by ''pbasista'' in the forum thread
 +
 +Otherwise your best option is to establish a serial connection to the device and then load the image via ''kermit'' (either directly copying it into the flash or booting an ''initramfs'' variant from memory and then flashing via ''OpenWrt'').
 +
 +Other variants and more information is provided in the aforementioned forum thread.
  
 </WRAP> </WRAP>
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 The C2 uses a external GBit switch, connected by MDIO bus. Network traffic to the CPU is passed through the internal switch of the MT7620A SoC: The C2 uses a external GBit switch, connected by MDIO bus. Network traffic to the CPU is passed through the internal switch of the MT7620A SoC:
-While the RTL8367R does support vid up to 4096, the driver for OpenWRT only allows vid 1-31, with 1,2 already used for OpenWRT itself. 
-Since this is driver limited, this is likely the case for all RTL8367R(B) based devices. 
  
 <code>             +---------------+ <code>             +---------------+
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  WAN   LAN1  LAN2  LAN3  LAN4</code>  WAN   LAN1  LAN2  LAN3  LAN4</code>
  
 +
 +
 +<WRAP center round info 60%>
 +Earlier versions of this article suggested “the driver for OpenWrt” (for the RTL8367R(B) switch chip) would have limited the range of usable 802.1q VLAN IDs to 1 – 31.
 +
 +While this may have been true for some earlier builds (could not confirm immediately), OpenWrt 21.02.3 (at least) no longer seems to suffer from such //hard// limit. There is still a //soft// limit which, for some reason, makes VLAN IDs above 31 unusable and non-working by default, but you can override this limit and use the full range of VLAN IDs by setting the ''enable_vlan4k'' option to ''1'' in the ''switch1'' section of the ''/etc/config/network'' configuration file, as follows:
 +
 +<code>
 +config switch
 +        option name 'switch1'
 +        option reset '1'
 +        option enable_vlan '1'
 +        option enable_vlan4k '1'
 +</code>
 +
 +If you edit the switch VLAN configuration in LuCI, it may add the ''enable_vlan4k'' configuration directive automatically for you. But for manual edits, you need to do it yourself to be able to get the higher-numbered VLAN IDs work.
 +</WRAP>
 +
 +<WRAP center round important 60%>
 +OpenWrt releases 21.02.0 — 21.02.3 (the latest official release as of this writing) appear to have a regression in their default network configuration which makes the inner (MT7620A) switch visible in LuCI as ''switch0'' for no real purpose, with a pseudo VLAN configuration that makes no sense.
 +
 +The router works as it should but configuring VLANs through LuCI may not work as expected and only the outer switch (''switch1'', RTL8367B) configuration is relevant. A bug report has been filed on this by the ID [[https://github.com/openwrt/openwrt/issues/8871|FS#3879 - Incorrect switch config for TP-Link Archer C2 AC750 #8871]].
 +
 +Until fixed in later releases, you can work around the issue by removing the extraneous ''switch0'' configuration from the file ''/etc/config/network''. This is best accomplished by issuing the following commands in the command line:
 +
 +<code>
 +uci delete network.@switch[0]
 +uci commit
 +reboot
 +</code>
 +</WRAP>
 ===== UBoot ====== ===== UBoot ======
  
  • Last modified: 2024/02/13 16:08
  • by jow