Try creating sockets again if network change occurs after bind failed.

p2p/client/basicportallocator.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 1087 matching lines @@
     return;
   }
 
   if (!((network == network_) && (previous_best_ip_ == network->GetBestIP()))) {
     // Different network setup; nothing is equivalent.
     return;
   }
 
   // Else turn off the stuff that we've already got covered.
 
-  // Every config implicitly specifies local, so turn that off right away.
-  *flags |= PORTALLOCATOR_DISABLE_UDP;
-  *flags |= PORTALLOCATOR_DISABLE_TCP;
+  // Every config implicitly specifies local, so turn that off right away if we
+  // already have a port of the corresponding type. Look for a port that
+  // matches this AllocationSequence's network, is the right protocol, and
+  // hasn't encountered an error.
+  // TODO(deadbeef): This doesn't take into account that there may be another
+  // AllocationSequence that's ABOUT to allocate a UDP port, but hasn't yet.
+  // This can happen if, say, there's a network change event right before an
+  // application-triggered ICE restart. Hopefully this problem will just go
+  // away if we get rid of the gathering "phases" though, which is planned.
+  if (std::any_of(session_->ports_.begin(), session_->ports_.end(),
+                  [this](const BasicPortAllocatorSession::PortData& p) {
+                    return p.port()->Network() == network_ &&
+                           p.port()->GetProtocol() == PROTO_UDP && !p.error();
+                  })) {
+    *flags |= PORTALLOCATOR_DISABLE_UDP;
+  }
+  if (std::any_of(session_->ports_.begin(), session_->ports_.end(),
+                  [this](const BasicPortAllocatorSession::PortData& p) {
+                    return p.port()->Network() == network_ &&
+                           p.port()->GetProtocol() == PROTO_TCP && !p.error();
+                  })) {
+    *flags |= PORTALLOCATOR_DISABLE_TCP;
+  }
 
   if (config_ && config) {
     if (config_->StunServers() == config->StunServers()) {
       // Already got this STUN servers covered.
       *flags |= PORTALLOCATOR_DISABLE_STUN;
     }
     if (!config_->relays.empty()) {
       // Already got relays covered.
       // NOTE: This will even skip a _different_ set of relay servers if we
       // were to be given one, but that never happens in our codebase. Should
@@ skipping 383 matching lines @@
   ServerAddresses servers;
   for (size_t i = 0; i < relays.size(); ++i) {
     if (relays[i].type == turn_type && SupportsProtocol(relays[i], type)) {
       servers.insert(relays[i].ports.front().address);
     }
   }
   return servers;
 }
 
 }  // namespace cricket