# DHCP falls back but no response to ping **URL:** \ **Category:** Rabbit Software\ **Tags:** rcm6700, dhcp\ **Created:** [July 19, 2018, 12:20pm UTC](https://forums.digi.com/t/dhcp-falls-back-but-no-response-to-ping/19733 "2018-07-19T12:20:17Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![shill](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@shill](https://forums.digi.com/u/shill)\ **Post date:** [July 19, 2018, 12:20pm UTC](https://forums.digi.com/t/dhcp-falls-back-but-no-response-to-ping/19733/1 "2018-07-19T12:20:17Z")
I am seeing issues with DHCP on RCM6700 using 10.72. Sometimes the module falls back to fallback address however I cannot ping the device. The network is the same, I simply reboot and try again and both DHCP or fallback can work. I have reverted back to running the DHCP.c example and can still see the problem. I am doing a soft reset to reproduce, sometimes it takes a number of restart program attempts to see the fail. I am pinging both the fallback and the dhcp address on a different machine. Anyone any suggestions on what is going on here or what I may be doing wrong? Thanks if you have read this far. This is the output with some debug when it fails: ========= DHCP.C ========= Enter the following keystrokes: 0-9 toggle specified interface up/down p ping a host P ping the same host again w do a HTTP HEAD request to specified host W HTTP HEAD from the same host again t print the interface, router, ARP and DNS server tables r add a router entry R delete a router entry n add a nameserver (DNS) entry N delete a nameserver entry f flush an ARP table entry i set new IP address and netmask IP: pkt\_init reserved 10 buffers at 000FB09A IP: i/f 0 using hwa :00:90:C2:FD:B4:FC Interface 0 is qualified for DHCP. Starting network (DHCP timeout 8 seconds)… Done sock\_init() TCP: -8217ms since last call to tcp\_tick! DHCP: Sending DISCOVER request on i/f 0 DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: overall timeout (6 sec) DHCP: Didn’t acquire lease on i/f 0 DHCP: Fallback to c0a896cd on i/f 0 Interface # 0 is now UP Network Parameters: My IP Address = C0A896CD Netmask = FFFFFF00 DHCP fell back to defaults Interface table: # IP addr. Mask Up Lnk Type MTU Flags Peer/router * * * 0 192.168.150.205 255.255.255.0 yes yes eth 1500 \*D S Nameserver list: = = = = = = = = = = = = = = = TCP: 291ms since last call to tcp\_tick! DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: Sending DISCOVER request on i/f 0 TCP: 200ms since last call to tcp\_tick! TCP: 101ms since last call to tcp\_tick! DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: overall timeout (6 sec) DHCP: Didn’t acquire lease on i/f 0 DHCP: Fallback to c0a896cd on i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: driving state machine for i/f 0 DHCP: Sending DISCOVER request on i/f 0 DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: retransmit in state 16 -\> 13 DHCP: Sending DISCOVER request on i/f 0 DHCP: overall timeout (6 sec) DHCP: Didn’t acquire lease on i/f 0 DHCP: Fallback to c0a896cd on i/f 0 DHCP: driving state machine for i/f 0 ---
**Author:** ![TomCollins](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.digi.com/tomcollins/32/37_2.png) [@TomCollins](https://forums.digi.com/u/TomCollins)\ **Post date:** [July 24, 2018, 8:15am UTC](https://forums.digi.com/t/dhcp-falls-back-but-no-response-to-ping/19733/2 "2018-07-24T08:15:38Z")
For your test, I assume you’re pinging from a machine with an IP address on the 192.168.150.x network, also with a netmask of 255.255.255.0. Please upgrade to Dynamic C 10.72D and see if that resolves the issue. Go to the “Development Software” section of this page to download the installer: [https://www.digi.com/support/productdetail?pid=4978](https://www.digi.com/support/productdetail?pid=4978) Or if you’re comfortable with using Git, you can work with this repository: [https://github.com/digidotcom/DCRabbit\_10](https://github.com/digidotcom/DCRabbit_10) I made a change that went into 10.72C related to DHCP fallback/recovery that may apply to your situation. [https://github.com/digidotcom/DCRabbit\_10/commit/62466f2893d921accc64602cabe3efae8302c1da](https://github.com/digidotcom/DCRabbit_10/commit/62466f2893d921accc64602cabe3efae8302c1da)