backup router settings to text file from the backup menu before any upgrade
after any major upgrade, do a hard reset (pin in back for 10 secs whilst powered on) and then restore settings
wireless repeating is wireless only i.e the 2nd access point in the chain is repeating a signal to wireless client ....its not repeating a signal to wired clients (usually) ...its also 1/2 duplex, so you lose 50% of whatever bandwidth you had available at the other access point
rule of thumb for repeating used to be find the point where original signal starts to decay, then go back 25% distance, locate repeater there to repeat strong signal e.g. the full 54Mbps
54Mbps is a real 25MBps of throughput (at best), then with one repeater hop that becomes 12Mbps, with 2 hops it would be 6Mbps..and latency gets worse each time (no good for gaming)
hence wireless repeating is always a last resort solution to get wireless access into an area where you cant just run an ethernet cable
bridging is a 2 way link that replaces an ethernet cable, and bridges all traffic, wired or wireless between 2 wired networks. You can have a wireless bridge connection without client association, if you just want to replace a cable, but dont want to provide wireless access in the 2nd location
It can all be a bit confusing, if you havnt learn the basics. In the early days of wireless networking there were different physical hardware devices for all these functions e.g. you wanted a bridge, you bought a bridge, you wanted an access point, you bought an access point....
...now, as sales volumes can be low, therefore price high on such niche purpose devices, manufacturers have tried to make "access points" which support all modes; repeater, bridge, access point, wireless to ethernet bridge
to confuse matters further, the consumer market refers to devices as "routers" which are really multi function devices that include; router, wireless access point, ethernet switch, firewall etc
then for some more consumer confusion, some of these "routers" dont necessarily support all the wireless modes that a dedicated "access point" does - they just tend to do a subset
IT is like the finance industry - keep it complex with lots of acronyms, so you can make a nice living out of understanding it all; 10 years ago if you could build a PC, you could make a nice living...now thats a commodity product, and commodity knowledge (any teenager can do it usually) and you can usually buy a PC far cheaper than you could build one out of bits ....
In another 10 years, no doubt basic networking skills will be commodity, common knowledge, everyone will know how to configure a basic home network with firewall, and the game will have moved on again to something else